Italian Treviso Radicchio Gratin | Radicchio di Treviso Gratinato all'Asiago
Radicchio di Treviso is not a salad leaf that happens to be red. The late variety, the tardivo, is frozen in the field on purpose, cut, then stood in running spring water in the dark for three weeks until it grows a second time without light. What comes out is a narrow head of white ribs and burgundy blades that snaps like celery and tastes assertively bitter. Heat softens that bitterness but never removes it, which is why a gratin works here and would be wasted on a mild vegetable.
The cheese has to be chosen against that bitterness rather than around it. Asiago d'allevo, aged on the plateau above Vicenza, has the dry granular body and faintly piquant caramel edge that meets radicchio on level ground. A young cheese melts into sweetness and the dish stops tasting of Treviso; a blue wins the argument outright. The method that follows is the one the region uses: heads seared in butter, braised in dry white wine, bound with a deliberately loose Asiago sauce and finished under the broiler, with everything hanging on keeping the leaves intact and the dish dry.
Yield: 6 side servings. Prep: 30 minutes. Cook: 45 minutes. Rest: 10 minutes. Total: about 1 hour 25 minutes. Difficulty: intermediate. Course: contorno. Region: Veneto, the plain between Treviso and Castelfranco.
The Story
Red chicory has been grown north of Venice for centuries, but the tardivo is a nineteenth century invention tied to one piece of geography: the resurgence springs of the Veneto plain, where water leaves the gravel at a constant 52°F (11°C) all winter. In the 1860s the technique of forcing frosted heads in that water was formalised around Dosson, Casier and Quinto di Treviso, and the agronomist Francesco Van den Borre is credited with turning the imbianchimento into a controlled process.
The heads take at least two real frosts in the field, which kills the outer leaves and concentrates everything inside. They are lifted with the taproot attached, stood upright in tanks of continuously running spring water and kept in total darkness for fifteen to twenty five days. Without light the new growth makes no chlorophyll, so the ribs come through brilliant white and the blades a translucent wine red. Each head is then stripped by hand to that inner heart and trimmed into the pointed shape sold under the Radicchio di Treviso IGP seal, protected since 1996.
Asiago comes down from the Altopiano dei Sette Comuni at around 3,300 feet (1,000 m). Two cheeses carry the name: pressato is young, moist and mild, while d'allevo is the mountain original, made from partly skimmed milk and aged four months to two years into a firm straw coloured paste with a long savoury finish. Putting the mezzano or vecchio on forced chicory is a pairing the Veneto arrived at by living with both, and it is why this gratin belongs to December and February, when the tardivo is in the Treviso markets.
Ingredients
For the radicchio
Radicchio di Treviso tardivo heads, 2 1/4 lb (1 kg), about 6 medium heads
Unsalted butter, 3 tbsp (42 g)
Extra virgin olive oil, 1 tbsp (15 ml)
Dry white wine, 1/2 cup (120 ml)
Fine sea salt, 1/2 tsp (3 g)
Freshly ground black pepper, to taste
For the Asiago sauce
Whole milk, 2 cups (480 ml)
Unsalted butter, 3 tbsp (42 g)
All purpose flour, 3 tbsp (24 g)
Asiago d'allevo mezzano, grated, 5 oz (140 g)
Freshly grated nutmeg, 1 small pinch
Fine sea salt, 1/4 tsp (1.5 g)
Ground white pepper, 1/4 tsp (0.5 g)
For the gratin topping
Asiago d'allevo vecchio, grated, 2 oz (55 g)
Parmigiano Reggiano, grated, 1 oz (28 g)
Dry coarse breadcrumbs, 1/3 cup (35 g)
Unsalted butter, melted, 1 tbsp (14 g)
For finishing
Extra virgin olive oil, 1 tbsp (15 ml)
Flat leaf parsley, chopped, 1 tbsp (4 g)
Freshly ground black pepper, to taste
Butter for the baking dish, 1 tsp (5 g)
Preparation
Trim, wash and halve the heads
Cut away the last inch of taproot but leave the crown intact, since it holds each half together through searing and baking. Strip any bruised outer blade and wash under cold running water, opening the leaves to clear the grit at the base. Split each head lengthwise through the root end and blot the cut faces dry. Never slice crosswise, and never leave the face damp: it will not brown.
Sear the halves in butter
Set a wide heavy skillet over medium high heat with the butter and olive oil and wait until the foam subsides and the butter smells nutty. Lay the halves cut side down in one layer, in two batches if needed, and sear undisturbed about 3 minutes until properly browned. Turn them, give the rounded side 2 minutes and season as they turn.
Braise with dry white wine
Pour in the wine, let it bubble hard for fifteen seconds to drive off the raw alcohol, then lower the heat, cover and braise 6 to 8 minutes. The leaf ends should go limp while the white rib keeps a slight resistance. Uncover, reduce what is left to a syrupy glaze of no more than a tablespoon, then lift the halves onto a rack to drain.
Build the besciamella base
Melt the sauce butter over medium low heat, add the flour at once and whisk 2 minutes without letting it colour. Warm the milk separately and add it in three additions, whisking each smooth before the next. Simmer gently 6 to 8 minutes until it coats a spoon thinly and tastes clean rather than floury, then season with salt, white pepper and nutmeg.
Fold in the Asiago off the heat
Take the pan off the burner and wait a full minute before adding the grated mezzano, then stir it in with a spatula. Aged Asiago is low in moisture and high in long protein chains: in a simmering sauce those proteins tighten and squeeze out their fat into grainy curds, while off the heat the cheese melts glossy. Loosen with warm milk until the sauce pours in a ribbon.
Assemble the gratin
Butter a shallow dish just large enough for one layer, about 9 by 13 inches (23 by 33 cm). Spread three tablespoons of sauce across the bottom and arrange the halves cut side up, crowns alternating so they interlock and lie flat. Spoon the rest over them, concentrating it on the leaf ends and leaving the white ribs partly exposed: a gratin drowned in sauce steams instead of browning.
Add the topping and bake
Toss the grated vecchio, the Parmigiano, the breadcrumbs and the melted butter with your fingers until the crumbs look evenly damp, then scatter them over the surface in a thin layer. Bake at 400°F (200°C) on the middle shelf for 18 to 20 minutes, until the sauce bubbles at the edges and the crust sets pale gold.
Finish under the broiler and rest
Move the dish to the upper third and switch to the broiler for 90 seconds to 2 minutes, standing at the door the whole time. The crust should go from gold to mottled deep brown and stop there. Drizzle over the olive oil, scatter the parsley, grind on pepper, then leave it alone 10 minutes so the sauce sets enough to cut cleanly.
Plating
Serve it hot but not scalding, around 145°F (63°C) in the centre, and bring it to the table in its baking dish whenever the meal allows, since a transferred crust is never the same crust. If you portion in the kitchen, warm the plates to roughly 120°F (50°C): a cold plate strips the heat out of a thin layer of vegetable within a minute and the fat stiffens on the rim.
Lift portions with a flat metal spatula slid under the crown, never a serving spoon, which tears the leaf ends and drags the crust off in sheets. One large half or two small ones make a serving. Lay them so the white rib and the browned face are both visible, and spoon any sauce left in the corners alongside the base rather than over the crust. Garnish almost invisibly, with parsley, a thread of olive oil and pepper from the mill, and send it out beside roast guinea fowl, grilled sausage, boiled beef or polenta.
Professional Technique
The technique that defines this dish is managing bitterness through heat rather than cancelling it with fat or sugar. The bitter compounds in forced chicory are sesquiterpene lactones, mainly lactucopicrin and intybin, concentrated in the white ribs and the root end. They are heat labile and partly water soluble, so every minute of cooking and every drop of liquid the vegetable gives up removes some. The sear and short braise take off roughly the top third, leaving the dish astringent rather than harsh. Boil it first and the Asiago has nothing left to push against.
The second is the split cheese load, because Asiago d'allevo behaves differently in the two positions. The mezzano, at eight to twelve months, still has the moisture and free fat to melt smoothly, so it goes in the sauce. The vecchio, past eighteen months and almost dry, would break in a sauce but is ideal on top: its low water content lets the surface dehydrate and crystallise under the broiler into a crisp sheet rather than a rubbery lid.
Texture and Moisture Control
Water attacks this gratin at four points. Washing water on the cut face stops the sear, so the halves are blotted. Braising liquid dilutes the sauce, so it is reduced to a glaze and the halves drained on a rack. Cell water released during baking thins the dish from inside, which is why the sauce is left loose. Condensation is the fourth: never cover this gratin with foil, since trapped steam softens a finished crust in under three minutes.
The target is three sensations in one bite: leaf ends almost melting, white rib still faintly fibrous, crust shattering. That gradient exists only because the rib is thicker than the blade and cooks more slowly, so one oven time gives two results in the same piece. Cut the heads into ribbons and it disappears, which is why halving through the crown is not a presentation choice.
The finish decides the crust. The 400°F (200°C) bake sets the sauce and cooks the vegetable through; the broiler only dehydrates and browns the surface. A longer hot bake overcooks the radicchio to mush before the top colours, and the broiler alone burns the crumbs while the sauce is still cold. Two stages, two purposes.
Professional Mise en Place
Almost everything here can be held and only the broiler stage is last minute. In a kitchen the gratin is assembled cold in the morning and fired to order.
Equipment and tools
Wide heavy skillet with a lid, large enough for six halves in one layer
Small heavy saucepan and a balloon whisk for the besciamella
Shallow gratin dish about 9 by 13 inches (23 by 33 cm), ceramic or enamelled cast iron
Box grater for the Asiago and a fine rasp for the nutmeg
Cooling rack for the braised halves, flat metal spatula for service
Prepared ahead
Radicchio washed, halved and blotted up to 6 hours ahead, on a rack in the refrigerator
Asiago sauce up to 1 day ahead, surface pressed with film to stop a skin forming
Topping mixture tossed and sealed in a container up to 2 days ahead
Radicchio seared, braised and drained up to 4 hours ahead, held at room temperature
Gratin assembled unbaked up to 6 hours ahead, kept cold and uncovered
Service setup
Oven at 400°F (200°C), middle shelf clear, broiler element ready above
Sauce warm and pourable, loosened with hot milk if it has tightened
Assembled dish out of the refrigerator 30 minutes before it goes in
Olive oil, parsley and pepper mill beside the oven for the finish
Plates warm, flat spatula to hand, 10 minutes of rest built into the timing
Chef Tips
Buy the tardivo with the taproot attached and the leaves still closed: the root proves it went through the forcing tanks, and flopped open blades mean it has been out of the water too long. If only the early round precoce is available the recipe still works, but cut the braise to 4 minutes.
Taste the Asiago before grating. The gap between a mezzano at eight months and one at fourteen is large and the older carries far more salt, so if yours tastes sharply savoury alone, cut the besciamella salt to a pinch and correct only after the cheese has melted in.
Save the braising glaze if there is more than a spoonful and whisk it into the finished sauce. It carries the wine acidity and the browned butter from the sear, and lifts a sauce that can otherwise taste flat against so assertive a vegetable.
If the gratin has to wait, hold it uncovered at 200°F (95°C) for up to 20 minutes: it loses a little crust and nothing else. What it must not do is sit under foil, which gives the one texture this dish never recovers from, a wet lid of crumbs over a cooling sauce.
Common Mistakes
Slicing the heads into ribbons. Cut crosswise the radicchio loses the crown that holds it together, collapses into a tangle and gives one uniform texture instead of three.
Thickening the besciamella too far. The radicchio releases water as it bakes, so a sauce that looks right in the pan arrives thin and broken. Build it lighter and let the vegetable finish the job.
Stirring the Asiago into a simmering sauce. Aged Asiago splits above roughly 175°F (80°C), leaving grainy protein and separated fat. Take the pan off the heat, wait a minute, then fold the cheese in.
Blanching the radicchio first. Boiling leaches out so much bitterness and colour that the gratin tastes only of cheese sauce and the blades turn dull brown.
Covering the dish with foil. Trapped steam softens the crust within minutes and it cannot be recrisped without overcooking what is underneath. Bake, rest and hold uncovered.
Leaving the broiler unattended. Crumbs and grated cheese go from mottled brown to acrid black in about 20 seconds under a hot element. Stay at the door and pull the dish when the colour is right.
Wine Pairing
Soave Superiore DOCG: Garganega from the volcanic soils east of Verona, and the most intelligent white here for a bitter vegetable. Its own bitter almond finish meets the radicchio as a partner rather than a corrective, while the acidity cuts the butter in the besciamella. The Superiore has the body to stand under aged Asiago.
Bianco di Custoza DOC: A blend from the moraine hills south of Lake Garda and the everyday bottle of this corner of the Veneto. Softer and more floral than Soave, with white peach and a herbal lift, and that softness works against the salt of a double cheese topping.
Lugana DOC: Turbiana from the clay flats at the southern end of Garda, and the structural choice here. It carries more weight and a saline drive that stands up to the broiled crust without turning heavy, with enough acidity to reset the palate after melted Asiago.
Bardolino DOC: The light red, from the eastern shore of the lake, for when this gratin sits beside grilled sausage or guinea fowl. Corvina and Rondinella give sour cherry fruit and bright acidity, and the low tannin matters: firm tannin against radicchio bitterness turns metallic. Serve at 57°F (14°C).
Conegliano Valdobbiadene Prosecco Superiore DOCG: In the brut version only, never dry or extra dry, whose residual sugar collides with the bitterness and makes both sides worse. Brut, the carbon dioxide scours the fat of the sauce off the palate and the green apple acidity refreshes without adding flavour. It is also the wine of the hills north of Treviso.
Storage & Reheating
Cooked and fully cooled, the gratin keeps refrigerated up to 3 days, covered with film in the baking dish or moved to an airtight container. Never cover it while any warmth remains, or condensation drips back onto the crust and leaves the surface waterlogged by morning.
Reheat uncovered at 350°F (175°C) for 15 to 18 minutes from cold, until the centre is hot and the edges bubble, then give it 60 seconds under the broiler to bring the top back. A microwave heats it in two minutes and turns the crust to paste. Single portions do well in a hot skillet, cut side down, covered 4 minutes then uncovered 2.
Do not freeze it. The besciamella separates on thawing and radicchio cells that have already cooked collapse completely, giving something closer to a purée than a gratin. To work ahead, assemble the dish unbaked, refrigerate up to 24 hours and bake straight from cold with 5 minutes added.
Nutrition
Per serving, based on 6 side servings:
Calories: 315 kcal
Total Fat: 22 g
Saturated Fat: 13 g
Trans Fat: 0.6 g
Unsaturated Fat: 8 g
Cholesterol: 62 mg
Sodium: 545 mg
Total Carbohydrates: 15 g
Fiber: 2.5 g
Total Sugars: 6 g
Added Sugars: 0 g
Protein: 14 g
Lactose: 3.6 g
Principal micronutrients: calcium, phosphorus, vitamin K, vitamin A, folate, potassium, anthocyanins from the red leaf
These figures are estimates. Sodium varies considerably with the age of the Asiago, since a vecchio wheel can carry half again as much salt as a mezzano.
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