Ingredients

  • 3/4 stick unsalted butter, plus additional to butter a 6-cup gratin dish
  • 6 tablespoons all-purpose flour
  • 2 cups whole milk
  • 1/2 teaspoon salt
  • 1/2 teaspoon freshly ground black pepper
  • 5 extra-large eggs
  • 2 1/2 cups grated Swiss cheese, preferably Gruyere (about 6 ounces)
  • 3 tablespoons minced chives

Method

  • Preheat the oven to 400F.
  • Butter a 6-cup gratin dish and set it aside.
  • Melt the 3/4 stick of butter in a saucepan, then add the flour and mix it in well with a whisk.
  • Cook for 10 seconds, add the cold milk in one stroke and mix it in with a whisk.
  • Keep stirring with the whisk until the mixture thickens and comes to a strong boil, about 2 minutes.
  • It should be thick and smooth.
  • Remove from the heat, and stir in the salt and pepper.
  • Break the eggs into a bowl and beat well with a fork.
  • After about 10 minutes the white sauce should be cool enough to proceed.
  • Add the eggs, cheese and the chives to the sauce, and mix well to combine.
  • Pour into the buttered gratin dish and cook immediately, or set-aside until ready to cook.
  • If setting aside for a few hours, the souffle can remain outside at room temperature.
  • If assembling a day ahead, refrigerate and bring back to room temperature before baking.
  • Bake for 30 to 40 minutes, or until puffy and well browned on top.
  • Although it will stay inflated for quite awhile, it is best served immediately.