Mousseline de Saumon à la Tosca

Ingredients

Equipment Needed

• •Food processor with metal blade
• •Fine-mesh sieve and flexible scraper
• •Digital scale accurate to 1 gram
• •Four ⅔-cup (150 ml) ramekins or oval moulds
• •Deep roasting pan for the bain-marie
• •Instant-read thermometer
• •Plain ovenproof oval serving platter

Instructions

1. 1

   Prepare the crayfish

   If the crayfish are frozen, thaw them completely in the refrigerator and pat them dry. Twist away all 20 tails and peel them carefully. Choose the 16 finest tails for the garnish and split each lengthwise into two clean halves, giving you eight halves for every Mousseline. Cover and refrigerate them. Roughly chop the remaining 4 tails for the cream-cullis, then crack the reserved shells and bodies with the back of a heavy knife.

2. 2

   Make crayfish foundations

   Put the cracked crayfish shells and bodies in a small heavy saucepan with the 8 tablespoons of butter. Cook over gentle heat for 10 to 12 minutes, pressing and turning the shells until the butter becomes deeply coral and smells distinctly of crayfish without browning. Strain it through a fine sieve, pressing firmly, and discard the shells. For the crayfish cream-cullis, combine the 4 chopped tails, ¼ cup cream, and 1 tablespoon (15 ml / 14 g) of the crayfish butter in a small pan. Simmer gently for 3 minutes, blend until smooth, pass through the fine sieve, and reduce until exactly 3 tablespoons (45 ml / 42.5 g) remain. If it reduces below that weight, restore it with cold cream a few drops at a time. Chill the cream-cullis completely.

3. 3

   Build the cold forcemeat

   Chill the food-processor bowl and blade for 15 minutes. Process the cold salmon with the measured salt and white pepper in short pulses until finely cut, then add the egg white and pulse just until absorbed. With the machine running briefly, pour in the 140 ml cold cream in a thin stream. Stop as soon as the mixture becomes smooth and glossy; it must remain below 10°C / 50°F. If it loses its gloss or beads liquid, stop immediately and set the bowl over ice for 10 minutes. Pulse again once cold. If it remains split, process the additional cold egg white in a clean chilled bowl, then feed in the broken mixture one spoonful at a time. Ça se rattrape. Press the forcemeat through a fine sieve, weigh out 1 pound (454 g), and fold in the cold 3 tablespoons (45 ml / 42.5 g) crayfish cream-cullis until the colour is even.

   Poach a teaspoon of the finished mixture in barely trembling water for 2 minutes. It should hold together, feel softly resilient, and taste properly seasoned. Make any salt adjustment before filling the moulds.
4. 4

   Mould and poach

   Heat the oven to 300°F / 150°C and butter four ⅔-cup (150 ml) ramekins or oval moulds. Divide the forcemeat evenly among them, about 4⅓ ounces (124 g) per mould, smooth the tops, and tap each mould once against a folded towel to release large air pockets. Set them in a roasting pan and add hot water at about 175°F / 80°C to come halfway up their sides. Cover the pan loosely with foil and poach for 18 to 22 minutes, until the centres reach 155°F / 68°C and spring back gently under a fingertip. If the water begins bubbling hard, remove the pan from the oven and replace a cupful with cool water before continuing; boiling toughens the edges while the centre is still setting.

   The water should barely quiver. Gentle, even heat lets the egg white set around the salmon emulsion without squeezing out its cream.
5. 5

   Make light Mornay

   Melt the 2 tablespoons butter in a saucepan, stir in the flour, and cook gently for 2 minutes without colouring. Whisk in the warm milk a little at a time, then add all but 1 tablespoon of the cream. Simmer gently for 5 to 6 minutes, whisking, until the sauce is nappant, thick enough to coat the back of a spoon while remaining light enough to flow. Remove it from the heat and stir in the Gruyère, Parmesan, salt, white pepper, and nutmeg. Whisk in 2 tablespoons (30 ml / 28 g) crayfish butter last. If the sauce looks oily, take it fully off the heat and whisk in the reserved cold cream; once smooth, keep it warm over barely hot water.

6. 6

   Brown the milt

   Pat the milt slices dry and season them lightly. Melt the tablespoon of butter in a small skillet and let it colour only to pale hazelnut. Add the milt and cook for 60 to 90 seconds per side, until lightly bronzed, opaque throughout, and at least 145°F / 63°C at the thickest point. Lift the slices onto a warm plate. Off the heat, turn the crayfish tail halves through a teaspoon of the remaining crayfish butter for 20 seconds, just long enough to gloss and warm them without making them tough.

7. 7

   Arrange the Tosca garnish

   Let the poached Mousselines rest in their moulds for 3 minutes, then run a thin knife around each edge and invert them onto a plain ovenproof oval platter. Arrange them in a circle, exactly as the source directs. Set one slice of browned milt on each Mousseline, arrange eight crayfish tail halves over and around it, and place one thin truffle slice at each end.

8. 8

   Coat and glaze

   Heat the broiler fully. Spoon the hot light Mornay over the Mousselines and their garnishes in an even coat, enough to cloak them without flooding the platter. Set the dish 2 to 3 inches below the heat and glaze quickly for 30 to 90 seconds, watching without interruption, until the sauce takes a faint golden blush and tiny bubbles catch around the edges. The broiler is doing the salamander's work, so speed matters. Bring the platter straight to the table. À table!

Chef Tips

• •Order salmon or cod milt from a trusted fishmonger before planning the dinner. Milt is la laitance, the soft roe of a male fish, not a dairy ingredient. It should smell clean and faintly marine, remain properly chilled, and be cooked the day you receive it.
• •Whole unseasoned crayfish are essential because the shells make the crayfish butter that runs through both the cream-cullis and Mornay. Good frozen crayfish are an honest choice and often preferable to tired fresh ones; avoid heavily spiced cooked crayfish because their seasoning will take over the sauce.
• •A preserved whole black truffle is the classical pantry's sensible answer when fresh truffle is unavailable. Drain and blot it well before slicing. Truffle oil cannot supply the slices or the restrained aroma this garnish requires.
• •The source observes that early-season vegetable purées suit Mousselines beautifully. Keep the Tosca garnish intact and serve a spoonful of pea or asparagus purée beside it, not over it. A dry Champagne or a mineral white Burgundy has enough freshness for the cream, cheese, and crayfish.

Advance Preparation

• •Make the crayfish butter and cream-cullis one day ahead. Refrigerate them separately in covered containers; warm only the butter needed for the Mornay, while the cream-cullis must remain cold for the forcemeat.
• •The light Mornay can be made up to 4 hours before serving. Press buttered parchment directly against its surface, refrigerate, then reheat over very gentle heat with a spoonful of milk if it has tightened.
• •Prepare the salmon forcemeat up to 2 hours before poaching and keep it covered in the coldest part of the refrigerator. Portion the milt and slice the truffle during that interval, but brown the milt and glaze the platter only at service.

Frequently Asked Questions

Nutrition Information

1 serving (about 300g)