Cheddar Cheese Puffs

Bahan-bahan (20 porsi)

• ½ cup salted butter (1 stick )
• ½ cup whole milk
• ½ cup water
• 1 teaspoon Dijon mustard
• ⅛ teaspoon cayenne pepper
• 1 cup all-purpose flour
• 4 large eggs
• 1½ cups sharp cheddar cheese (grated )
• 2 stalks scallions (cut into small rounds)