Gruyère Cheese Soufflé

Ingredients

• 1¼ cups grated Gruyère
• 3 tbsp butter, plus more for the dish
• 3 tbsp flour
• 1 cup whole milk, warmed
• 4 eggs, separated, plus 1 extra white
• 2 tbsp finely grated parmesan, for dusting
• 1 tsp Dijon mustard
• 1 pinch cayenne
• 1 pinch cream of tartar
• Salt and white pepper

Method

1. Heat the oven to 375°F (190°C) with a rack in the lower third. Butter a 6-cup soufflé dish and dust it with parmesan — this rough coating is the ladder the soufflé climbs.
2. Make a thick béchamel: melt the butter, whisk in the flour for 1 minute, then add the warm milk gradually and cook until very thick. Off the heat, beat in the yolks one by one, then the Gruyère, Dijon, cayenne, salt, and white pepper. Season boldly; egg whites mute everything.
3. Whip the 5 whites with the cream of tartar to glossy medium peaks — droopy tips, not rigid spikes.
4. Loosen the base with a third of the whites, then fold in the rest in wide, patient strokes until just combined. Streaks are forgivable; deflation is not.
5. Fill the dish, run a thumb around the inner rim for a clean crown, and bake 25–28 minutes until tall, golden, and barely wobbly at the center. Serve within ninety seconds — physics is undefeated.