Filets de Soles Grand Duc

Ingredients

Equipment Needed

• •12-inch (30 cm) wide shallow sauté pan with lid
• •2-quart (1.9 L) oval broiler-safe serving platter
• •1½-quart (1.4 L) heavy saucepan
• •Fine-mesh sieve
• •Flexible fish spatula
• •Small skillet
• •Instant-read thermometer

Instructions

1. 1

   Prepare the sole

   Heat the oven to 325°F (165°C). Run a fingertip over each sole fillet and remove any pin bones, then trim only ragged edges. Dry the fillets carefully and season them with half the salt and the white pepper. Fold each fillet once, bringing the thicker end over the thin end while leaving its pointed tail visible; keep them cold while you prepare the foundations.

   Choose fillets of similar thickness. Eight even fillets finish together, while one heavy piece can force the thinner ones to wait themselves dry.
2. 2

   Make mushroom liquor

   Put the sliced mushrooms, water, 1 tablespoon butter, and a small pinch of the measured salt in a saucepan. Cover and hold at a gentle simmer for 10 minutes, until the mushrooms have surrendered their liquor but remain pale. Strain through a fine sieve without crushing them hard; measure ¾ cup (180 ml) of the clear cooking liquor and set it aside. The mushrooms have done their work here, so save them for an omelette or soup rather than crowding them onto this platter.

3. 3

   Build the Mornay base

   Melt the 2 tablespoons butter in a saucepan, stir in the flour, and cook this pale roux for 2 minutes without letting it color. Whisk in the warm milk gradually, making each addition smooth before adding the next. Hold at a quiet simmer for 5 minutes, whisking along the bottom, until the sauce is nappant, thick enough to coat the back of a spoon. Cover its surface directly and keep it warm; the poaching liquor and cheeses enter later.

4. 4

   Blanch the asparagus

   Bring a saucepan of well-salted water to a lively boil. Add the asparagus tips and cook for 2 to 3 minutes, until vivid green and barely tender when pierced. Refresh them at once under very cold running water, then drain and dry them thoroughly. This stops their cooking now so they can be heated in butter at the final moment without losing their color.

5. 5

   Poach the fillets

   Butter a wide shallow pan with 1 teaspoon of the softened butter and arrange the folded fillets in a single layer. Pour the fish fumet and the reserved mushroom cooking liquor around them, then cover closely with a lid or a round of parchment. Bring the liquid just to a tremble on the stove and transfer the pan to the oven for 6 to 9 minutes. Lift the sole as soon as it is barely opaque at the thickest fold, around 135°F (57°C); the glaze will finish it. Never let the liquor boil. Hard bubbling tightens these delicate fillets, and no sauce can give that tenderness back.

6. 6

   Finish the Mornay

   Lift the sole carefully with a fish spatula and let each fillet drain while loosely covered. Strain the poaching liquor into a clean saucepan and boil it down to ½ cup (120 ml), tasting near the end because its salt concentrates. Whisk the reduction and all but 1 tablespoon of the cream into the warm roux base, then simmer until it falls from the whisk in a broad ribbon. Take it off the heat before stirring in the Gruyère, Parmesan, nutmeg, and cold finishing butter. Do not boil after the cheese enters. If the Mornay turns oily or grainy, stop heating it. Ça se rattrape: whisk in the reserved cold cream a teaspoon at a time, then pass the sauce through a fine sieve. If it is too thick, loosen it with a spoonful of milk; if thin, reduce it before adding the cheeses.

7. 7

   Compose the platter

   Heat the broiler fully and set its rack about 6 inches (15 cm) from the element. Butter an oval broiler-safe platter with the remaining teaspoon of softened butter. Arrange the eight folded fillets in an oval with their pointed tails facing inward, exactly as the dish requires. Set one fine truffle slice in the middle of each fillet and place three crayfish tails between each neighboring pair. Spoon the Mornay evenly over the whole arrangement, coating it without burying its shape. If liquid seeps from the fish and thins the coating, tip it back into the saucepan and reduce briefly before trying again.

8. 8

   Glaze it quickly

   Slide the platter beneath the broiler for 2 to 4 minutes, watching without leaving it, until the Mornay blisters lightly and colors butter-gold at its highest points. This is a glaze, not a second bake. The fish should reach 145°F (63°C) at its thickest fold without drying. If the sauce remains pale after 3 minutes, move the platter slightly closer rather than extending the cooking.

9. 9

   Crown with asparagus

   While the platter glazes, melt the remaining 2 tablespoons butter in a small skillet. Add the asparagus tips with the last of the salt and toss only until hot, glossy, and lightly cohered by the butter. As soon as the platter leaves the broiler, heap the very green tips in its center and carry it directly to the table. The glaze should gleam, the sole should yield at the touch of the serving spoon, and the asparagus should still have a clean bite. À table!

Chef Tips

• •Dover sole gives the finest, firmest fillets, but evenness matters more than grandeur. Ask for skinless fillets close to 2½ ounces (70 g) each. Lemon sole is the nearest honest cousin when Dover sole is unavailable; thin flounder fillets work, though their flesh is softer.
• •The fumet must taste clean and concentrated, never muddy or aggressively salty. Homemade or good frozen fish fumet is ideal. If yours tastes weak, reduce it before measuring; the poaching liquor is the spine of the Mornay.
• •Frozen cooked crayfish tails are the classical pantry's honest answer when live crayfish are unavailable. Thaw them slowly in the refrigerator and dry them well, because excess water loosens the glaze.
• •When fresh truffle is out of season, use a preserved whole truffle in its liquor. It carries less aroma but keeps the required slice and earthy depth. Truffle oil supplies neither and overwhelms the sole.
• •The serving platter must be genuinely broiler-safe. Limoges-style porcelain made for oven service or a shallow gratin dish will do; decorative china can crack under direct heat.
• •Pour a dry white Burgundy with enough acidity for the Mornay, or a brut Champagne for a celebration. Keep the accompaniments quiet: small buttered potatoes are plenty beside a dish already carrying its own asparagus.

Advance Preparation

• •Make the mushroom cooking liquor up to one day ahead, cool it promptly, and keep it covered in the refrigerator. Warm it with the fumet before poaching.
• •Prepare the Mornay base through the milk stage up to 4 hours ahead. Press parchment directly onto its surface, refrigerate it, and reheat gently before adding the reduced poaching liquor, cream, cheeses, and finishing butter.
• •Blanch, refresh, and dry the asparagus tips up to 6 hours ahead. Keep them chilled between clean towels, then bind them with butter only as the sole goes beneath the broiler.
• •Thaw and dry the crayfish tails earlier in the day. Slice the truffle shortly before assembling so its cut surfaces retain their aroma.
• •Poach, compose, and glaze the sole just before serving. Holding the finished platter softens the asparagus, tightens the fish, and lets the Mornay lose its gloss.

Frequently Asked Questions

Nutrition Information

1 serving (about 380g)