Golden Chicken and Mushroom Soufflé

Preheat the oven to 400°F (200°C). Generously grease an ovenproof baking dish and set aside.

In a saucepan over medium heat, melt the butter. Add the flour and cook for 1–2 minutes, stirring constantly, until smooth and lightly fragrant.

Gradually whisk in the milk, stirring continuously to form a smooth, lump-free sauce. If needed, strain the sauce and return it to the pan.

Bring the sauce to a gentle simmer, stirring, until slightly thickened.

In a bowl, beat the egg yolks until smooth. Slowly stir them into the hot sauce along with the mustard, stirring constantly over low heat for 2–3 minutes. Remove from heat.

Season with salt and black pepper. Fold in the chopped chicken and fried mushrooms until evenly combined.

In a clean, dry bowl, whisk the six egg whites to stiff, glossy peaks.

Gently fold the egg whites into the chicken mixture in two to three additions, using a spatula to preserve as much air as possible.

Transfer the mixture to the prepared dish, smooth the top, and sprinkle evenly with the grated cheese.

Bake on the middle rack for about 45 minutes, until puffed, golden, and just set in the center. Serve immediately.

Optional: For an extra-light texture, place the baking dish in a larger pan filled halfway with hot water (bain-marie) before baking.