Preparation Steps

• Preheat oven to 400°F (205°C). Line a baking sheet with parchment paper or a silicone mat.
• In a medium saucepan, combine butter, water, and milk. Bring to a rolling simmer over medium heat, stirring until butter is melted.
• Remove pan from heat and add the flour all at once. Stir vigorously with a wooden spoon until a smooth dough forms and pulls away from the sides of the pan. Return to low heat and stir 1 minute to dry the dough slightly.
• Transfer dough to a mixing bowl and let cool 2 minutes. Add eggs one at a time, beating well after each until fully incorporated and dough is smooth and glossy.
• Stir in grated cheddar, salt, pepper, and mustard powder until evenly distributed.
• Use a small cookie scoop or two spoons to drop heaping tablespoonfuls of dough onto the prepared baking sheet, spacing about 1.5 inches apart.
• Bake 20–25 minutes, or until puffed and deep golden brown. Do not open the oven during the first 15 minutes to prevent collapse.
• Remove from oven and transfer puffs to a wire rack to cool slightly before serving warm.