Preheat oven to 400°F.
Line two baking sheets with parchment paper.
Pre-measure all ingredients. Set aside.
Add the water, milk, salt, and butter into a medium saucepan and cook over medium heat. Stir often until the mixture comes to a boil. Immediately turn the heat down to low.
Stir in the all-purpose flour until the Pâte à Choux dough is completely incorporated. It will pull away from the saucepan and a film will form on the sides. Immediately remove the from the heat.
Using a rubber spatula, move the Choux Pastry mixture into a mixing bowl and let it cool for 3 minutes. Sprinkle on the nutmeg and pepper.
Add one egg to the mixture.
Stir the egg briskly with a wooden spoon. It will not incorporate at first. Keep stirring until combined. The dough with be glossy.
Repeat with the last three eggs making sure each is incorporated completely before adding the next.
Stir in 1 1/4 cups of the Gruyère cheese only.
Using a tablespoon cookie scoop, place the small rounded Gougères Pâte à Choux mounds onto the prepared baking sheets two inches apart.
Sprinkle with the remaining cheese. I sprinkle each with a little more salt and pepper. Completely up to you.
Bake for 20 minutes or until they are puffed and golden.
Turn on that oven light!!!! AVOID OPENING THE DOOR UNTIL THEY ARE GOLDEN! THEY WILL DEFLATE!
Remove from the oven and cool completely at room temperature on a baking rack. Serve warm or at room temperature.