Saumon en CroûteSalmon en Croûte with Fish Mousse

Check the thawed pastry and keep it refrigerated

• 1 Check that 750 g pastry has thawed in the refrigerator according to its package directions and is flexible but still cold. Keep it covered in the refrigerator while completing steps 2–6.

Cut and blanch the mousse vegetables

• 1 Cut the 80g mousse carrot into 2mm brunoise, fine dice, and slice 75g green beans into 5mm pieces.
• 2 Bring 500 ml water to a boil in a small saucepan. Cook the beans separately for 4 minutes, the carrots for 2 minutes and the 75 g peas for 2 minutes, using the same water and bringing it back to a boil before each vegetable. As soon as each vegetable is cooked, lift it out with a skimmer and immediately transfer it to cold water.
• 3 When all the vegetables are cold, drain in a strainer and pat dry with paper towels.

Process cod with eggs and fold in vegetables for the mousse

• 1 Cut 250g cold Pacific cod into 2cm pieces and process with 3g salt for 1 minute until smooth.
• 2 Add 2 cold eggs and process for another 30 seconds, then add 0.2g white pepper.
• 3 Transfer to a bowl and evenly fold in the blanched vegetables with a flexible spatula.

Sandwich the mousse between 2 salmon fillets and wrap in plastic wrap

• 1 Remove any remaining pin bones from the 2 salmon fillets, pat dry and season the inward-facing surfaces with 3g salt and 0.3g white pepper.
• 2 Stack 2 sheets of plastic wrap, each 60cm long, and lay them out. Place the first fillet on them with the inward-facing side up.
• 3 Spread the mousse evenly about 2cm thick, then place the second fillet inward-facing side down on top, aligning the shapes.
• 4 Roll tightly in the wrap from the near edge, twist and tie the ends, then wrap again in another sheet in the same way.

Poach in court-bouillon to 70°C at the center

• 1 Use a deep pot large enough to submerge the parcel, at least 28cm across or an oval pot at least 32cm long. Add 2.5L water, 200g carrot rounds, 150g sliced onion, 2 thyme sprigs, 1 bay leaf, 2 cloves, 10 peppercorns and 20g salt. Bring to a boil over high heat, then simmer on low for 10 minutes.
• 2 Keep just below boiling, with small bubbles at the edges, submerge the parcel and poach for 15 minutes. If it floats, weigh down with a heatproof plate.
• 3 Continue poaching in 5-minute increments as needed until the parcel center reaches 70°C.

Chill the poached parcel in ice water and the refrigerator

• 1 Immerse the wrapped parcel in ice water for 20 minutes.
• 2 Wipe dry and refrigerate for 60 minutes.

Wrap the salmon in pastry and mark scales with a knife tip

• 1 Preheat the oven to 180°C and line a baking sheet with parchment.
• 2 Once the pastry is thawed but still cold, divide and roll the 750 g into two sheets about 3 mm thick and 27 × 36 cm. On a floured surface, roll 1 sheet 5 cm larger than the salmon in both directions and put it on the baking sheet; return the other sheet to the refrigerator.
• 3 Unwrap the salmon, pat dry with paper towels and place in the pastry center. Lift the pastry edges against its sides and trim overlapping pieces.
• 4 Dilute the glazing yolk with 1 teaspoon water and brush the raised pastry edges.
• 5 Cover with the 2nd pastry sheet from the refrigerator, trim excess and press its sides onto the lower pastry with your fingers.
• 6 Brush yolk over the entire surface and lightly press scale patterns from tail toward head with the tip of a round-tipped knife.

Bake at 180°C while making the mousseline sauce base

• 1 Bake on the middle rack at 180°C for 20–25 minutes.
• 2 MeanwhileWhile baking, whip 80ml cream to soft peaks and refrigerate.
• 3 MeanwhileAt the same time, melt 125g unsalted butter over low heat in a small saucepan and keep warm.
• 4 MeanwhileAt the same time, put 2 yolks and 30ml water in a bowl over a water bath at about 80°C and whisk for 3–4 minutes until thick.
• 5 MeanwhileOnce the yolks have thickened, remove the bowl from the water bath and whisk in the melted butter in a thin stream. Add 10 ml lemon juice, 1 g salt and 0.1 g white pepper to make hollandaise.

Rest for 5 minutes, slice and serve with sauce

• 1 Leave the baked pastry on its baking sheet for 5 minutes.
• 2 Gently fold the whipped cream into the hollandaise with a flexible spatula to make sauce mousseline and transfer to a serving bowl.
• 3 Cut into 3cm slices with a serrated knife, plate and serve with the sauce.