MAKES ABOUT  2½ DOZEN INGREDIENTS ½ cup milk 8 tbsp. unsalted butter, cubed ½ tsp. kosher salt 1 cup flour 4 eggs, at room temperature 6 oz. Gruyère cheese, grated INSTRUCTIONS 1. Heat oven to 425°. Bring milk, butter, salt, and ½ cup water to a boil in a 4-qt. saucepan over high heat. Add flour; stir until dough forms. Reduce heat to medium; cook, stirring dough constantly with a wooden spoon, until slightly dried, about 2 minutes. Transfer to a bowl; using a hand mixer, beat in 1 egg until smooth. Repeat with remaining eggs, beating each one at a time, until dough is smooth; stir in cheese. 2. Using a large tablespoon, drop balls of dough onto parchment paper-lined baking sheets. Place in oven; reduce temperature to 375°. Bake until golden brown, about 30 minutes.