Paupiettes de Merlan au Gratin

Ingredients

Equipment Needed

• •Food processor with metal blade
• •12-inch (30 cm) round gratin dish, about 2-quart capacity
• •Small skillet
• •Flexible fish spatula
• •Instant-read thermometer

Instructions

1. 1

   Chill the equipment

   Put the food processor bowl and blade in the cold for ten minutes. Keep the diced fish, egg white, and cream chilled until the moment you need each one. Cold is part of the technique here: the fish protein must bind the cream into a smooth forcemeat rather than release its fat.

2. 2

   Make the forcemeat

   Process the diced whiting with ½ teaspoon of the salt and half the white pepper until it forms a smooth, tacky paste. Add the egg white and pulse only until absorbed. With the machine running in short bursts, add all but 1 tablespoon of the cream gradually, stopping as soon as the mixture becomes pale, glossy, and firm enough to hold the trail of a spoon. Fold in the fines herbes, the finely chopped fresh herb mixture, by hand. If the forcemeat turns greasy or grainy, stop immediately. Ça se rattrape: set the bowl over ice until thoroughly cold, then pulse briefly, adding the reserved cream one teaspoon at a time only as the mixture smooths.

   Poach a teaspoon of forcemeat in barely simmering water for two minutes. It should set tenderly without leaking liquid; taste it, correct the seasoning, and return the remaining mixture to the cold.
3. 3

   Cook the mushroom caps

   Melt 1 tablespoon of the butter in a small skillet over medium heat. Add the 8 whole mushroom caps, season with a pinch of the remaining salt, and cook for four to five minutes, turning them until lightly bronzed and just tender. Set them aside. Leave the sliced mushrooms raw, exactly as the construction requires; they will cook in the sauce around the paupiettes.

4. 4

   Build the sauce bed

   Heat the oven to 400°F (200°C) with a rack in the upper third. Butter a 12-inch (30 cm) round gratin dish with 1 tablespoon of the butter and scatter the shallots evenly across its floor. Spread the first ¾ cup of prepared gratin sauce from Gratins (No. 268) over the shallots in an even bed. If the chilled sauce is too firm to spread, stir it gently until supple rather than heating it to a boil.

5. 5

   Fill and roll

   Dry the whiting fillets well and lay them with the former skin side facing upward. Season lightly with the remaining salt and white pepper. Divide the cold forcemeat among them, about 1½ tablespoons per fillet, and spread it in a thin, even coat while leaving a narrow border. Roll each fillet from its narrow tail end toward the thicker end, making a compact scroll without squeezing out the filling. If a thin fillet tears, overlap the edges and continue; set it seam-side down and the roll will hold as it cooks.

6. 6

   Arrange the gratin

   Set the paupiettes seam-side down on the sauce bed, leaving a little space between them. Arrange the raw sliced mushrooms as a border around the rolls and place one cooked mushroom cap on top of each. Spoon the second ¾ cup of prepared gratin sauce from Gratins (No. 268) around and lightly over the paupiettes, leaving the mushroom crowns visible. Scatter the breadcrumbs evenly across the top and dot them with the remaining 2 tablespoons of butter.

7. 7

   Bake without rushing

   Bake for eighteen to twenty-two minutes, until the sauce bubbles at the rim, the mushrooms have softened, and the centre of a paupiette reaches 145°F (63°C). If the sauce tightens enough to expose the bottom of the dish before the fish is cooked, spoon 2 tablespoons of hot water around the rim and cover loosely with foil for the remaining minutes. The sauce will loosen without washing away its character.

8. 8

   Gratinate and serve

   Turn the broiler to high and set the gratin beneath it for one to two minutes, just until the breadcrumbs bronze and the butter glistens across the crust. Watch without walking away. If the fish is already cooked but the top remains pale, this brief gratinating heat gives colour without drying the paupiettes. Rest for three minutes, then serve two scrolls per person with mushrooms and plenty of sauce. À table!

Chef Tips

• •Ask for thin, flexible whiting fillets of roughly equal size. Hake or pollock can stand in when whiting is unavailable, but the fillets must be thin enough to roll without splitting and mild enough to let the forcemeat and gratin sauce lead.
• •Keep the processor bowl, fish, egg white, and cream cold. If the processor bowl feels warm beneath your hand, stop and chill it; forcing a warm forcemeat only makes the emulsion coarser.
• •Have the finished gratin sauce from Gratins (No. 268) ready before you begin. Its preparation belongs to its own formula, and this recipe reaches for it as the classical kitchen did: complete, seasoned, and ready to use.
• •Serve with a dry, brisk white wine, such as Muscadet or an unoaked white Burgundy. Acidity is useful beside the butter, cream, and mushrooms; sweetness is not.

Advance Preparation

• •The prepared gratin sauce from Gratins (No. 268) can be made a day ahead and kept covered in the cold. Stir it until supple before assembling the dish, loosening it with a spoonful of water only if necessary.
• •The forcemeat can be prepared up to four hours ahead and held over ice or in the cold, tightly covered. Keep it cold and fold the fines herbes through only once.
• •The paupiettes may be assembled in their sauce up to two hours ahead. Keep the dish covered and chilled, then add the breadcrumbs and butter immediately before baking. Do not bake the fish ahead, since reheating tightens both fillet and filling.

Frequently Asked Questions

Nutrition Information

1 serving (about 370g)