Seared Scallops with Jerusalem Artichoke Cream, Piedmont Hazelnuts and Black Truffle | Capesante Scottate con Crema di Topinambur, Nocciole Piemonte IGP e Tartufo Nero
This is a Piedmontese plate that happens to have a scallop on it. The topinambur is the subject: a knobbly tuber that tastes of artichoke heart and roasted chestnut and behaves like no other root vegetable in the kitchen, because it stores its carbohydrate as inulin rather than starch. Around it sit two more things the Langhe produces, the Tonda Gentile hazelnut and black truffle, and the scallop is there to give all of it a sweet, saline anchor.
The whole dish turns on the cream. Inulin does not gelatinise, which means a topinambur purée will never thicken the way a potato one does and has to get its body from slow cooking, a little fat and two passes through a fine sieve. Get that right and you have a sauce with the texture of heavy cream and the flavour of a vegetable most people have never properly tasted. Get it wrong and you have watery soup with a scallop floating in it.
Yield: 4 servings. Prep: 30 minutes. Cook: 40 minutes. Total: about 1 hour 10 minutes. Difficulty: advanced. Course: antipasto or light secondo. Region: Piedmont, the Langhe and the Monferrato.
The Story
Topinambur reached Europe from North America early in the seventeenth century and was named after the Tupinamba, a Brazilian people paraded around Paris in 1613, which is the wrong continent entirely. The English name is wronger still: Jerusalem has nothing to do with it and is a worn down version of girasole, sunflower, which is what the plant is. In Italy it took hold in the north and went half wild along the riverbanks of Piedmont and Lombardy, where it still grows in thickets nobody planted.
In Piedmont it became one of the vegetables of the bagna caoda. Through late autumn in the Langhe and the Monferrato the raw sliced tuber goes to the table with cardoons to be dipped into hot garlic and anchovy sauce, which tells you two things. Piedmontese cooks have always respected its raw crunch. And the anchovy in that pot came up the salt roads from Liguria on the backs of the acciugai, the anchovy men, which is how a landlocked region built a cuisine around a preserved sea fish. A scallop on a Piedmontese plate is less strange than it looks.
The hazelnut is the Tonda Gentile Trilobata, grown in the Alta Langa around Cortemilia and protected as Nocciola Piemonte IGP. It is round, its skin comes away cleanly when roasted, and its oil content is high enough that it turns to paste under pressure, which is why gianduia was invented here. The truffle is the black one on purpose: Alba is white truffle country, but white truffle collapses under heat, while black truffle keeps its perfume against butter and a warm plate.
Ingredients
For the scallops
Large sea scallops, side muscle removed, 12, about 1 lb 2 oz (510 g)
Unsalted butter, 2 oz (55 g)
Grapeseed or sunflower oil, 1 tbsp (15 ml)
Fresh thyme sprigs, 2
Flaky sea salt and freshly ground white pepper, to taste
For the Jerusalem artichoke cream
Jerusalem artichokes, topinambur, 1 lb 5 oz (600 g)
Lemon, halved, for the acidulated water, 1
Shallot, thinly sliced, 1
Unsalted butter, 1 1/2 oz (40 g)
Whole milk, 1 cup (240 ml)
Heavy cream, 1/3 cup (80 ml)
Bay leaf, 1
Fine sea salt, 3/4 tsp (4.5 g)
For the hazelnuts and the crisps
Nocciola Piemonte IGP hazelnuts, shelled, 3 oz (85 g)
Jerusalem artichoke, extra, for the crisps, 3 oz (85 g)
Sunflower oil for frying, 2 cups (475 ml)
Fine sea salt, 1 small pinch
For finishing
Fresh black truffle, 1/2 oz (15 g)
Unsalted butter for the hazelnut butter, 1 oz (30 g)
Lemon juice, a few drops
Chives, finely sliced, 1 tsp
Preparation
Step 1
Trim and hold the topinambur. Scrub the tubers hard under cold water and peel them with a small knife, following the knobs rather than fighting them, and drop each piece straight into water acidulated with the juice of half a lemon. Cut flesh browns within a minute in air, and a cream built from oxidised pieces comes out grey instead of ivory. Slice the peeled tubers thinly and keep them under the water until the pan is ready.
Step 2
Cook the cream base. Melt the butter in a heavy saucepan, add the shallot and sweat it over low heat for 5 minutes without letting it colour. Drain the topinambur, add it with the bay leaf and stir to coat. Pour in the milk, bring it to a bare simmer and cook covered for 25 minutes, until a slice crushes against the side of the pan with no resistance. Do not let it boil hard, since milk that boils will catch and taste scorched.
Step 3
Blend and pass it twice. Remove the bay leaf, add the cream and blend the mixture hot until it is completely smooth, working in two batches rather than crowding the jug. Pass it through a fine mesh sieve, then pass it again. The second pass is not fussiness: topinambur skin fragments and fibre survive every blender, and one sieve leaves them behind. Season with salt, keep the cream warm and never let it boil again.
Step 4
Fry the topinambur crisps. Slice the extra tuber on a mandoline as thinly as you can, rinse the slices in cold water to wash off surface starch and dry them thoroughly between towels. Fry them at 300°F (150°C) for 3 to 4 minutes, until the bubbling slows and they are pale gold. Lift them onto paper, salt them at once and keep them dry and uncovered. They crisp fully as they cool.
Step 5
Roast and skin the hazelnuts. Roast the hazelnuts at 325°F (165°C) for 10 to 12 minutes, until the skins crack and the kitchen smells of them. Tip them hot into a clean towel, fold it over and rub firmly: Tonda Gentile skins come away almost completely, which is exactly why this variety is used for pastry. Chop two thirds of them coarsely for the plate and leave the rest whole for later use.
Step 6
Prepare the scallops. Pull off the small tough side muscle from each scallop, the crescent of tighter fibre that sits against the round of the adductor, and discard it. Lay the scallops on a tray lined with paper and leave them uncovered in the refrigerator for 20 minutes so the surface dries. Salt them only as they go into the pan, because salt applied earlier draws moisture back to the surface and undoes the drying.
Step 7
Sear the scallops in hazelnut butter. Heat the oil in a heavy pan until it shimmers, lay the scallops down in a single ring and leave them alone for 90 seconds. Add the butter and the thyme, let the butter foam and turn the colour of the hazelnuts beside it, then tilt the pan and baste the tops for 30 seconds. Turn them, give them 20 seconds more and lift them out. The centre should still be translucent.
Step 8
Finish and shave the truffle. Whisk the tablespoon of hazelnut coloured butter from the pan with a few drops of lemon juice to make a dressing for the plate. Brush the truffle clean with a dry brush, never under a tap, and shave it directly over the warm plates at the moment of service. Truffle aroma is volatile and fat soluble, so it needs warmth and butter beneath it and no cooking at all.
Plating
Use flat white plates, warmed but not hot, since a plate above blood heat starts cooking the underside of the scallops while they wait. Spoon three tablespoons of topinambur cream into the centre and spread it outward into a wide shallow disc, leaving a clean margin. The cream should sit still: if it creeps toward the rim it needs another two minutes of reduction.
Set three scallops on the cream, seared side up, spaced evenly rather than stacked. Spoon the hazelnut butter dressing around them, scatter the chopped hazelnuts and two or three crisps so they stand at an angle, and add the chives. Shave the black truffle over everything last, at the table if you can, and finish with flaky salt on each scallop and no pepper on the truffle itself.
Professional Technique
Inulin is the reason this dish is harder than it looks. Where a potato stores energy as starch, topinambur stores it as inulin, a chain of fructose units that does not swell, does not gelatinise and does not thicken anything. A potato purée builds its body from burst starch granules; a topinambur purée has nothing equivalent, so thickness has to come from reducing the cooking liquid, from butter and cream, and from removing fibre by sieving. Cooks who treat it like potato produce a thin, gritty sauce and blame the vegetable.
Inulin also explains the flavour and the notorious after effect. Slow cooking hydrolyses part of the chain into free fructose, which is why a properly cooked topinambur tastes distinctly sweeter than a raw one. The rest passes through the small intestine undigested and ferments in the colon, which is where the tuber earned its unkind Italian nicknames. Long gentle cooking reduces that, and so does serving it as a modest amount of sauce rather than a plate of roasted chunks.
Cut topinambur browns faster than apple or artichoke because it is rich in polyphenol oxidase, the enzyme that turns exposed phenols brown on contact with oxygen. Acidulated water works by dropping the pH below the range where that enzyme functions, not by rinsing anything away, which is why pieces go into the water as they are cut. The colour of the finished cream, ivory rather than grey, is decided in the first two minutes of knife work.
Texture and Moisture Control
A scallop is almost entirely adductor muscle and around three quarters water, and its proteins begin to tighten at about 120°F (49°C). Taken to the centre it goes from tender to springy to chalky within a very short span, so the target is a crust on one side and a centre still translucent, which means leaving the pan at roughly 115°F (46°C) in the middle and carrying over on the plate. A scallop cooked through has lost the dish.
The cream and the crisps pull in opposite directions. The cream tightens as it cools and thins if it is warmed too aggressively, so hold it covered at around 150°F (65°C) and adjust with a spoonful of hot milk. The crisps have no defence at all, being dry fried slices with nothing binding them, and they go leathery within seconds of touching the cream. They go on last and they lean, never lie.
Professional Mise en Place
Everything except the scallops and the truffle can be finished before service. The sear takes two and a half minutes and nothing else can be happening while it does.
Equipment and tools
Heavy skillet, cast iron or thick steel, large enough for 12 scallops without crowding
High speed blender and a fine mesh conical sieve
Mandoline for the crisps and a truffle shaver
Small heavy saucepan for the cream and a bain marie to hold it
Dry brush for the truffle, fish spatula, offset spatula
Prepared ahead
Topinambur cream, up to 1 day ahead, refrigerated and rewarmed gently
Hazelnuts roasted, skinned and chopped, on the day, kept airtight
Crisps fried up to 4 hours ahead and left uncovered in a dry place
Scallops trimmed and drying uncovered in the refrigerator, 20 minutes before service
Truffle brushed clean and wrapped in paper inside a sealed jar
Service setup
Cream warm over a bain marie with hot milk beside it for adjustment
Pan preheating dry, butter and thyme portioned within reach
Plates warm but never hot, crisps and hazelnuts at the pass
Truffle and shaver kept at room temperature, not cold
Chef Tips
Choose the smoothest topinambur in the box. The knobblier the tuber the more of it you lose to peeling, and a bumpy one can waste a third of its weight before it reaches the pan. Buy firm ones with tight skin and no soft spots, and use them within a week, since they shrivel faster than potatoes.
Store the truffle properly. Wrap it in kitchen paper, change the paper daily and keep it in a sealed jar in the refrigerator, where it holds three or four days. Rice is the classic advice and it is wrong, because rice pulls moisture out of the truffle and gives you a dry one and some faintly perfumed rice.
Taste the cream against a scallop, not on its own. Topinambur is naturally sweet and a scallop is sweeter, so a cream seasoned to taste correct from a spoon will often read as flat once the two meet. Push the salt slightly further than feels right and use the lemon in the butter to draw a line under both.
Without truffle the dish still works, and it is honest to say so. Replace it with a teaspoon of hazelnut paste stirred into the finishing butter and a little more of the chopped nuts. It is a different plate, quieter and nuttier, but it is not a compromised version of this one.
Common Mistakes
Peeling the whole batch before it goes into water. Polyphenol oxidase greys the cut surfaces within a minute and the finished cream carries that colour to the plate. Every piece goes into acidulated water as it is cut, not after.
Expecting it to thicken like potato. Inulin does not gelatinise, so no amount of blending will build body. Thickness comes from the milk reducing, from the butter and cream, and from taking fibre out through the sieve.
Boiling the milk. Milk driven hard against the base of the pan catches and the scorched note travels through the whole cream, which cannot be corrected afterwards. Keep it at a bare simmer under a lid.
Sieving once. A single pass leaves fibre that reads as grit under a smooth sauce, and it is the most common reason a home version feels rough. Pass it twice, pressing with a ladle.
Salting the scallops early. Salt draws moisture back to a surface you have just spent 20 minutes drying, and a wet scallop steams instead of browning. Season them as they meet the pan.
Cooking the truffle. Heat drives off the volatile compounds that carry its perfume and leaves an expensive piece of fungus tasting of very little. It is shaved over the plate at the last second and never goes near the pan.
Wine Pairing
Roero Arneis DOCG: The Piedmontese white this dish was practically designed for, from the sandy left bank of the Tanaro. Arneis finishes on a bitter almond and hazelnut note that lines up with the Tonda Gentile, and it carries enough weight to sit against a buttery cream.
Erbaluce di Caluso DOCG: From the morainic hills north of Turin, and the sharpest knife in this set. Its acidity is uncommonly high for an Italian white and it cuts straight through the butter and the cream, resetting the palate between scallops. The faintly stony finish stays out of the truffle's way.
Alta Langa DOCG: Piedmont's metodo classico, Pinot Nero and Chardonnay aged at least thirty months on the lees. That ageing gives a bread and toasted nut character that meets the hazelnuts directly, while the mousse and acidity lift a rich plate.
Gavi DOCG: Cortese from the southeastern corner of Piedmont, lean, citrus driven and distinctly saline. That salinity is the point here: it echoes the sea in the scallop on a plate otherwise made entirely of inland ingredients, and its restraint leaves the truffle alone.
Collio Friulano DOC: A step outside Piedmont for anyone who wants more aromatic weight. Friulano is broad and textural with a faint herbal note that suits earthy vegetables, and it has the body to stand up to black truffle where a lighter white would vanish under it.
Storage & Reheating
Seared scallops do not keep and should never be made ahead. The cream is the only component that stores properly: up to 3 days airtight in the refrigerator, or 2 months frozen, although freezing costs it some smoothness and it needs blending and sieving again on thawing. Rewarm it over a bain marie, stirring, and loosen it with hot milk.
Crisps keep 2 days in an airtight tin with a piece of kitchen paper, but only if they were fully dry when they went in. Roasted hazelnuts keep a week airtight and go stale faster once chopped, so chop them on the day. Truffle holds three or four days wrapped in paper in a sealed jar, and if it begins to soften, grate what is left into soft butter and freeze that.
Nutrition
Per serving, based on 4 servings:
Calories: 590 kcal
Total Fat: 41 g
Saturated Fat: 17 g
Trans Fat: 0.7 g
Unsaturated Fat: 22 g
Cholesterol: 95 mg
Sodium: 720 mg
Total Carbohydrates: 30 g
Fiber: 4 g
Total Sugars: 12 g
Added Sugars: 0 g
Protein: 26 g
Lactose: 5 g
Principal micronutrients: potassium, iron, vitamin B12, magnesium, vitamin E, phosphorus
These figures are estimates. Most of the frying oil is discarded rather than eaten, and the inulin in the topinambur is counted as carbohydrate here although the body does not absorb it as sugar.
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