- 1/2 cup butter
- 1 cup flour
- 5 eggs
- 1 cup grated gruyère cheese
- 1/2 cup grated parmesan cheese
- 2 teaspoons Dijon mustard
- 1 teaspoon freshly ground black pepper
How to Make It
Preheat oven to 425°. Heat butter and 1 cup water in a medium saucepan over medium heat until butter is melted and mixture comes to a simmer.
Turn heat to low, add flour, and stir vigorously until mixture forms a ball that pulls away from pan sides, about 1 minute. Remove pan from heat.
Add eggs, one at a time, stirring vigorously after each. Dough will separate after each addition; keep stirring until it forms a smooth paste.
Stir in gruyère cheese, parmesan cheese, Dijon mustard, and freshly ground black pepper.
Drop mixture in heaping tablespoonfuls onto 2 buttered baking sheets. Bake until puffed and brown, about 30 minutes. Cut slits in sides of puffs, return to oven, and lower heat to 350°. Bake 10 minutes.