Spinach Souffle with Leeks and Gruyere Cheese

4 tablespoons butter, divided

1¼ cups grated Gruyere cheese, divided

1 cup half-and-half

1 small leek, white and light green parts roughly chopped

1 garlic clove, peeled

12 ounces fresh spinach, rinsed

4 tablespoons flour

1¼ cups milk

1 teaspoon salt

4 egg yolks

6 egg whites, room temperature

Heat oven to 375 degrees. Grease a 5- or 6-cup soufflé dish or gratin dish with 1 tablespoon of the butter. Dust the dish with 1/4 cup grated Gruyere.

Warm the half-and-half in a small pan over medium-low heat. Add the leek and garlic clove and bring to a boil. Remove from heat and cover; let stand 15 minutes. With a slotted spoon, remove leeks and garlic, discard. Meanwhile, heat the spinach in a pan with a little water until wilted; squeeze out excess water and chop.

Melt remaining butter in a saucepan; stir in flour 1 tablespoon at a time, cooking for about 1 minute between each addition. Whisk in milk and continue whisking until mixture thickens. Add salt and remaining Gruyere and stir until cheese has melted. Remove from heat and stir in egg yolks, spinach and cream.

Whip the egg whites until soft peaks form, adding a pinch of salt halfway through. Fold egg whites into spinach mixture. Pour batter into prepared dish and bake about 30 minutes.

Serves six to eight.