Italian Roasted Celeriac with Lentils, Walnuts and Salsa Verde | Sedano Rapa Arrosto, Lenticchie, Noci e Salsa Verde
Updated: Oct 24
This is a winter vegetable plate assembled from three Italian traditions that never met on one dish until recently. A whole celeriac is roasted under salt until the flesh turns sweet and almost custardy, then cut into wedges and coloured hard in a pan. Underneath goes a bed of small dark lentils cooked with a soffritto so fine it disappears. Over the top goes salsa verde, the parsley, caper and anchovy sauce northern Italy has served with boiled meat for two centuries.
Nothing here imitates meat. The celeriac is simply treated the way a butcher treats a cut, with a long slow cook followed by a hard sear, and the salsa verde is not adapted at all: the same sauce, built the same way, doing the same job of cutting richness with vinegar and salt.
Yield: 4 side servings. Prep: 30 minutes. Cook: 1 hour 25 minutes. Rest: 15 minutes. Total: about 2 hours 10 minutes. Difficulty: intermediate. Course: contorno. Region: a northern Italian plate, from Piedmont and Lombardy through Umbria and upper Lazio.
The Story
Celeriac is a late arrival in Italy and has never entirely stopped sounding foreign. The swollen rooted celery was selected in northern Europe during the sixteenth and seventeenth centuries and spread through Germany, Poland and the Low Countries long before it crossed the Alps. It entered Italian kitchen gardens from the north, through Trentino, Friuli and the Veneto, and mostly stayed there, grated raw into winter salads or dropped into broth. Only in the last thirty years have Italian cooks begun roasting it whole.
The lentils carry much older credentials. The lentil of Castelluccio di Norcia grows at around 1500 metres on the Piano Grande in Umbria, in thin soil and cold nights that give it a skin fine enough to need no soaking and a flavour far more mineral than a plains lentil. On the volcanic ground of the Tuscia around Onano in upper Lazio, another ancient lentil was grown from at least the sixteenth century, nearly lost after the war and brought back by a few growers. Both hold their shape.
Salsa verde is the Piedmontese and Lombard contribution and the oldest technique on the plate. In Piedmont it is bagnet verd, in Lombardy simply salsa verde, and in both it exists for one reason: to sit beside bollito misto and keep the palate awake through hours of boiled meat. Parsley, capers, salted anchovy, garlic, vinegar and a slice of bread soaked in that vinegar, pounded together and loosened with oil. On a sweet roasted root it does exactly the same job.
Ingredients
For the celeriac
Celeriac, whole, 2 lb (900 g) each, 2 roots
Coarse sea salt for the roasting bed, 2 lb (900 g)
Extra virgin olive oil, 3 tbsp (45 ml)
Unsalted butter, 1 tbsp (14 g)
Fresh thyme sprigs, 3
Freshly ground black pepper, to taste
For the lentils
Lenticchie di Castelluccio or Onano, 1 cup (190 g)
Shallot, very finely diced, 1 medium
Carrot, very finely diced, 1 small
Celery stalk, very finely diced, 1
Garlic clove, whole, 1
Bay leaf, 1
Extra virgin olive oil, 2 tbsp (30 ml)
Vegetable stock or water, 2 1/2 cups (600 ml)
Fine sea salt, 3/4 tsp (5 g)
For the salsa verde
Flat leaf parsley leaves, packed, 2 cups (50 g)
Salted anchovy fillets, rinsed, 4
Capers in salt, rinsed and drained, 2 tbsp (18 g)
Garlic clove, small, 1
White wine vinegar, 2 tbsp (30 ml)
Soft white bread, crust removed, 1 slice (25 g)
Extra virgin olive oil, 1/2 cup (120 ml)
Hard boiled egg yolk, 1, optional
For the walnuts and finishing
Shelled walnut halves, 1/2 cup (60 g)
Extra virgin olive oil, 1 tsp (5 ml)
Flaky sea salt, a pinch
Finely grated lemon zest, from 1/2 lemon
Celery leaves, pale inner, a small handful
Preparation
Roast the celeriac whole in salt
Heat the oven to 400°F (200°C). Scrub the roots hard under cold water but do not peel them: the skin protects the flesh and comes away easily later. Spread the coarse salt in a deep roasting tray, sit the roots on it and roast for 65 to 75 minutes, until a thin skewer slides into the centre with no resistance. The salt bed is not a crust and does not season through the skin. It draws moisture off the underside and stops the root stewing.
Cook the lentils with a fine soffritto
While the roots are in the oven, sweat the shallot, carrot and celery in the olive oil over low heat for 10 minutes without letting them colour. The dice should be small enough to vanish into the finished lentils. Add the lentils, garlic and bay leaf, stir for a minute, then pour in the stock. Simmer very gently, uncovered, for 20 to 25 minutes. Salt only in the last 5 minutes: skins toughen if salt goes in at the start.
Finish and season the lentils
They are ready when tender but each one still holds its shape and the liquid has reduced to a loose glaze rather than a soup. Remove the garlic and bay leaf, taste for salt, add a few drops of vinegar and hold them warm. Lentils keep absorbing liquid as they sit, so aim slightly wetter than you want at the table.
Build the salsa verde
Tear the bread into a bowl and pour the vinegar over it, pressing until fully soaked, then squeeze out most of the liquid. Chop the parsley, anchovy, capers and garlic together on a board until very fine, or pound them in a mortar. Work in the bread and the egg yolk if you are using it, then add the oil in a slow thin stream, stirring constantly. The sauce should be loose and spoonable, not a paste.
Toast the walnuts
Spread the walnut halves on a small tray and toast at 350°F (175°C) for 7 to 8 minutes, then toss them while warm with the teaspoon of oil and a pinch of flaky salt. Stay close to the oven: the gap between correctly toasted and irreversibly bitter is under a minute. Break them with your fingers, so you keep large pieces that crack under the tooth.
Peel and cut the roasted roots
Let the roots stand 15 minutes, which firms the flesh enough to cut cleanly. Pull the skin away with a small knife, working from the flat base upward: it should lift in sheets. Cut each root into thick wedges through the core, about 1 1/4 inch (3 cm) at the widest point. Wedges hold together under a sear in a way slices never do.
Sear the wedges in butter and oil
Heat a heavy skillet over medium high heat with the remaining oil until it shimmers. Lay the wedges in on their widest face and leave them alone for 3 minutes, until the underside is mahogany. Turn them, add the butter and thyme, and baste for 2 minutes as the butter foams and browns. Grind pepper over and take the pan off the heat. They go straight to the plate, while the edges still crackle.
Plating
Serve on warm wide plates at around 130°F (54°C). Spoon the lentils slightly off centre into a shallow oval, loose rather than packed into a dome. Lean two or three wedges against them with the seared faces turned toward the diner, so the contrast between dark crust and pale flesh is visible from a seated position.
Spoon the salsa verde over the wedges in a broken line, not a blanket, and let some fall onto the lentils. The plate needs areas without it, so the palate gets sweet roasted root on one forkful and sharp green sauce on the next. Scatter the walnuts over, finish with the lemon zest and a few pale celery leaves, and serve at once.
It holds its own beside roast beef or a braise and is strong enough to stand as a winter lunch with bread and a salad. Served alongside meat, halve the salsa verde so it does not compete.
Professional Technique
The technique that defines this dish is roasting the celeriac whole and unpeeled before it is ever cut. Celeriac is roughly eighty eight percent water and riddled with air channels, so a peeled and diced root loses moisture fast and ends up dry at the edges while the middle is still raw. Left whole in its skin it cooks in its own trapped steam, the starches break down slowly and the sugars concentrate, and the flesh finishes dense and faintly sweet. Only then can it take a hard sear.
The salt bed is a heat management device, not a seasoning one. Coarse salt has far lower thermal conductivity than a metal tray, so it moderates the heat hitting the base and stops the underside scorching before the centre is cooked, and it wicks away liquid that would otherwise pool and boil. None of it penetrates the skin.
The third technique is stabilising the salsa verde with soaked bread. Vinegar and olive oil will not stay combined on their own, and a salsa verde without a binder separates within twenty minutes on the plate. The crumb, soaked in vinegar and squeezed, provides a starch and gluten network that holds the oil in suspension and gives the sauce body enough to sit on a wedge instead of running off it. This is why bagnet verd survives a long lunch without splitting.
Texture and Moisture Control
Three textures have to reach the table intact. The celeriac must be yielding inside with a genuinely crisp seared face, so the surface has to be dry when it meets the pan: steam still escaping from a freshly peeled root prevents browning entirely. The 15 minute rest does that drying. If the wedges still feel damp, blot them before they go in.
The lentils must stay individual. That depends on gentle heat and late salting, but also on the liquid: too much stock and they sit in broth and go slack, too little and they scorch and split. Two and a half cups of stock to one cup of lentils, simmered uncovered so the liquid reduces as they absorb it, ends with a glaze that clings rather than a soup pooling under the celeriac.
The walnuts and the sauce sit on opposite sides of the moisture problem. Walnuts go soft within minutes of touching wet sauce, so scatter them last and never stir them into anything. If the salsa verde tightens while it waits, loosen it with a teaspoon of warm water rather than more oil, which would make it greasy and mute the vinegar.
Professional Mise en Place
The long roast dominates the timeline. Start the celeriac first, cook the lentils while it roasts, and make the sauce during the rest.
Equipment and tools
Deep roasting tray that holds both roots on a bed of salt
Heavy skillet, cast iron or carbon steel, for the sear
Mortar and pestle, or a heavy knife and a board, for the sauce
Small saucepan for the lentils and a fine mesh sieve
Thin skewer for testing the roots, paring knife for the skin
Prepared ahead
Celeriac roasted whole and unpeeled, refrigerated up to 2 days ahead
Lentils cooked and cooled, refrigerated up to 3 days ahead
Salsa verde made up to 1 day ahead, covered with a film of oil
Walnuts toasted and stored airtight at room temperature, up to 3 days
Soffritto diced and kept cold, on the day
Service setup
Lentils warm over low heat, loosened with stock if needed
Celeriac peeled and cut into wedges, held dry at room temperature
Skillet hot and empty, ready for the wedges at the last moment
Salsa verde at room temperature, stirred once before it goes out
Plates warmed to around 130°F (54°C), walnuts and zest within reach
Chef Tips
Choose the heaviest roots for their size, with no soft patches at the base and no hollow sound when tapped. Celeriac goes woolly at the centre as it ages, and no cooking method recovers a root that has already gone.
Make the salsa verde by hand. A blender emulsifies it too thoroughly and turns the parsley a dull army green within an hour, because the blades bruise the leaves and release the enzymes that destroy the colour. A board and a sharp knife give a sauce that stays bright.
Let the anchovies do the salting. Rinse them well, taste one, and season the sauce only after the anchovy and capers are already in it. Between them they carry a great deal of salt, and a salsa verde salted twice is inedible on a vegetable that has none of its own.
Without fish, leave the anchovy out and add a teaspoon of Dijon mustard and an extra spoonful of capers. It is not the same sauce, but it keeps the salt and sharpness in balance rather than leaving a hole.
Common Mistakes
Peeling and dicing the celeriac before roasting. Cut surfaces lose moisture immediately and the pieces dry out at the edges while the centre stays firm. Roast the roots whole in their skin and cut them afterwards.
Searing wedges that are still hot and damp. Steam still leaving the flesh prevents any browning at all and the pan turns into a steamer. Rest the roots 15 minutes, peel, cut and blot before the pan.
Salting the lentils at the start. Salt early in the cook toughens the skins and a fine skinned Castelluccio lentil will stay stubbornly firm however long it simmers. Add the salt in the final 5 minutes.
Making the salsa verde in a blender. It over emulsifies, dulls the colour to army green within the hour and produces a paste rather than a sauce. Chop by hand or use a mortar.
Leaving the bread out of the sauce. Without the soaked crumb the oil and vinegar separate on the plate and the sauce slides off the wedges in a slick. The bread is structural, not a filler.
Wine Pairing
Roero Arneis DOCG: The Piedmontese white that belongs with a Piedmontese sauce. Arneis from the sandy left bank of the Tanaro gives white peach and a distinct bitter almond finish over moderate acidity, and that bitterness runs alongside the parsley rather than fighting it. It has enough weight to sit under the roasted root without being flattened by the anchovy.
Erbaluce di Caluso DOCG: The sharper option from the moraine hills north of Turin, and the better choice if you have been generous with the sauce. Erbaluce has unusually high natural acidity for an Italian white and a stony, almost lemon pith character that meets the vinegar on its own terms. Serve it around 50°F (10°C), so the acidity stays taut against the sweet celeriac.
Dolcetto d'Alba DOC: The everyday red of the Langhe and the one most often on the table when bagnet verd appears. Dolcetto is deeply coloured but low in acidity and soft in tannin, with dark cherry fruit and a bitter almond twist that echoes the walnuts. The low acid profile is the point: a high acid red over a vinegar sauce turns metallic.
Barbera d'Asti DOCG: For the version served beside roast meat rather than alone. Barbera brings high acidity and almost no tannin, so it slices through the oil in the sauce without adding astringency to a plate that already has bitter greens and walnut skin. Choose an unoaked bottling: new wood and salsa verde sit badly together.
Oltrepò Pavese Metodo Classico DOCG: The Lombard sparkling answer, built largely on Pinot Nero. A brut from these hills has firm acidity, a fine persistent bead and a light red fruit core that stands up to the anchovy better than a leaner sparkler would. The bubbles lift the oil off the palate, which matters on a dish with half a cup of it in the sauce.
Storage & Reheating
Store the three components separately and the dish reassembles perfectly. Roasted celeriac, still unpeeled, keeps covered in the refrigerator for up to 3 days and is in some ways better on the second, since the flesh firms and sears more cleanly. Cooked lentils keep 3 days airtight. Salsa verde keeps 3 days under a film of olive oil, though the colour is brightest on the first day.
To reheat, bring the lentils back over low heat with a spoonful of stock, stirring gently so they do not break. Peel and cut the cold celeriac and sear it straight from the refrigerator, an extra minute per side; a cold wedge browns better because there is less surface moisture. Bring the salsa verde to room temperature and stir it before serving. Never microwave any part of this dish.
The lentils freeze well for up to 2 months in a sealed container, thawed overnight in the refrigerator. Do not freeze roasted celeriac, which collapses into a wet sponge as its cell walls rupture, and do not freeze the salsa verde, which separates irreversibly and loses the herb aroma.
Nutrition
Per serving, based on 4 side portions:
Calories: 480 kcal
Total Fat: 33 g
Saturated Fat: 5 g
Trans Fat: 0 g
Unsaturated Fat: 27 g
Cholesterol: 12 mg
Sodium: 780 mg
Total Carbohydrates: 36 g
Fiber: 12 g
Total Sugars: 5 g
Added Sugars: 0 g
Protein: 14 g
Lactose: 0.1 g
Principal micronutrients: folate, iron, potassium, phosphorus, manganese, vitamin K, vitamin C
These figures are estimates. Sodium depends almost entirely on how thoroughly the anchovies and salted capers are rinsed, and the fat figure is driven by the olive oil in the sauce.
Comments