Gougères

Bahan-bahan (36 porsi)

• ½ cup (1 stick) unsalted butter
• ½ cup water
• ½ cup milk
• ½ teaspoon sea salt
• ⅛ teaspoon ground nutmeg
• 1 cup all purpose flour
• 4 large eggs
• 1 cup shredded Gruyere cheese, (divided)
• 1 large egg yolk
• 1 tablespoon water