Heat the oven to 400°F. Line two large rimmed sheet pans with parchment paper and set aside.
In a medium pot over high heat, bring 1 cup of water, the butter, salt, and nutmeg to a boil.
Remove from the heat and pour in the flour. Stir vigorously with a wooden spoon until well incorporated. Return the pot to medium-low heat and stir constantly until the mixture forms an elastic-like ball, about 2 minutes.
Place the ball of dough in a large bowl. Add the eggs, one at a time, stirring to incorporate well after each addition. Using your hands, work the grated cheese into the dough.
Using either a spoon or a pastry bag fitted with a large round tip, dollop a tablespoon of dough onto the prepared sheet pan, leaving 1 inch between each dollop. Sprinkle with sesame seeds (if using).
Cook until golden brown and a gougère sounds hollow when tapped on its top, 16–18 minutes. Watch them carefully and do not overcook.