Spinach soufflé

Ingredients:

• 2 x 280g packages frozen chopped spinach, thawed
• 3 tablespoons unsalted butter
• 3 tbsp. flour
• 1.5 cups of milk
• 0.5 tsp coarse salt
• 1/4 teaspoon freshly grated nutmeg
• 1/4 tsp ground black pepper
• 3 large eggs, separate the yolks from the whites
• 1/8 tsp cream of tartar
• 0.5 tbsp. grated parmesan
• 1 tbsp. grated pecorino
• Cooking spray or softened butter to grease the pan

Preparation:

1. Preheat oven to 190°C. Place the spinach in a colander to drain. Squeeze out as much excess liquid as possible.
2. Prepare the béchamel sauce:
   
   In a medium saucepan over medium heat, melt the butter; add the flour and stir until it forms a thick paste. Add the milk 1/2 cup at a time, stirring well after each addition, until a smooth sauce forms. Remove from heat and add salt, nutmeg, and black pepper. Taste. Set aside and let the sauce cool slightly.
3. Beat the egg whites with a mixer until foamy. Add the cream of tartar and beat on high speed until stiff peaks form. Set aside.
4. Whisk the egg yolks in a large bowl until pale yellow, then gradually add the warm béchamel sauce. Using a rubber spatula, gently fold in the spinach, Parmesan, and 1/2 cup of pecorino. Fold in a third of the beaten whites to lighten the mixture, then gently fold in the remaining egg whites until fully incorporated.
5. Lightly spray a 2-quart soufflé dish with cooking spray or grease with softened butter, then add the remaining 1/2 cup pecorino, coating the bottom and sides of the dish. Add the soufflé batter and bake until the soufflé is puffed and golden, 25-30 minutes. Serve immediately.