Salmon and Spinach Souffle

Butter the inside of a 1.5-litre souffle dish generously, brushing upward strokes from base to rim. Add the grated Parmesan and tilt to coat the entire interior; tap out any excess. Refrigerate the prepared dish until needed. Separate the eggs, placing all 6 whites in a large, scrupulously clean bowl and the 4 yolks in a separate bowl. Grate the Gruyere. Mince the shallot and garlic. Warm the milk in a small saucepan until just steaming.

Place the salmon in a shallow pan, cover with cold water, add a pinch of salt, and bring to a bare simmer over medium-low heat. Poach for 6–8 minutes until the salmon just flakes when pressed and reaches an internal temperature of 63°C on a meat thermometer — the safe minimum for fish. Remove, drain, and flake into small pieces, discarding any grey flesh.

Place a large skillet over medium-high heat and add the spinach with just the water clinging to its leaves. Cook, tossing frequently, for 2–3 minutes until fully wilted and bright green. Transfer to a clean tea towel and squeeze firmly until completely dry. Roughly chop and set aside.

Melt the butter in a medium heavy-bottomed saucepan over medium heat. Add the shallot and garlic and cook, stirring, for 2 minutes until softened but not coloured.

Add the flour to the pan and stir constantly with a wooden spoon for 1 minute to cook out the raw flour taste, forming a pale roux.

Add the white wine and stir vigorously for 30 seconds until absorbed. Gradually add the warm milk, a ladleful at a time, whisking constantly until the bechamel is thick, smooth, and pulls away from the sides of the pan — about 3–4 minutes.

Remove from heat. Stir the Dijon mustard, nutmeg, salt, white pepper and grated Gruyere into the hot bechamel until the cheese is fully melted. Beat in the 4 egg yolks one at a time, incorporating fully before adding the next. Fold in the flaked salmon and chopped spinach. Set the mixture aside to cool for 10 minutes until barely warm to the touch.

Preheat the oven to 200°C, or 180°C for a fan oven, or 400°F. Place a baking sheet on the centre rack to heat.

Whisk all 6 egg whites with a pinch of salt using a stand or hand mixer on medium speed until foamy, then increase to high and beat until stiff, glossy peaks form that hold their shape without drooping — do not overbeat to dry peaks.

Fold one large spoonful of the beaten whites into the salmon base using a spatula to lighten it.

Add the remaining whites in two additions, folding with confident, sweeping strokes from the bottom of the bowl upward, rotating as you go — stop as soon as no white streaks remain.

Pour the mixture immediately into the prepared chilled souffle dish; it should fill to within 1cm of the rim. Run your thumb around the inner rim to create a shallow channel, which encourages an even, top-hat rise.

Place the dish on the preheated baking sheet and bake for 28–30 minutes until the souffle has risen 4–5cm above the rim, the crown is deep golden brown, and the dish wobbles very slightly when nudged — the interior should remain just set and creamy. Do not open the oven door during the first 25 minutes. Serve at once.