Classic Mushroom Cheese Soufflé

Preheat the oven to 350°F (175°C). Place a deep baking tray on the middle rack and carefully fill it halfway with hot water to create a bain-marie.

Clean the mushrooms thoroughly, chop them very finely, and gently squeeze them by hand to remove excess moisture.

Melt butter in a pan over low heat. Add the mushrooms, season lightly with salt and black pepper, and cook gently until all released liquid has evaporated. Set aside.

In a separate saucepan, prepare a béchamel by melting butter, stirring in flour, and gradually whisking in milk until smooth and thick. Remove from heat and let cool slightly.

Generously butter a heat-resistant soufflé dish and dust lightly with flour, tapping out any excess.

In a bowl, beat the egg yolks with a pinch of salt until pale. Stir them into the warm béchamel, then add grated cheese, nutmeg, and the cooked mushrooms. Mix until well combined.

In a clean, dry bowl, beat the egg whites until stiff peaks form. Gently fold them into the mushroom mixture in two to three additions, preserving as much air as possible.

Pour the batter into the prepared dish, smooth the top, and place carefully into the bain-marie.

Bake for 45 minutes without opening the oven door. Check doneness with a fork; if it comes out clean, the soufflé is ready. If needed, bake an additional 10–15 minutes.

Serve immediately while puffed and golden for the best texture and presentation.