In a small heavy saucepan combine the milk, 1/4 cup water, the butter, and the salt. Bring the mixture to a boil over high heat. Reduce the heat to moderate, add the flour all at once, and beat the mixture with a wooden spoon until it leaves the side of the pan and forms a ball. Transfer the mixture to a bowl, whisk in the eggs, one at a time, whisking well after each addition and stir in the Parmesan and pepper to taste. Drop the batter in 8 mounds on a buttered baking sheet and bake the puffs in the upper third of a preheated 400 oven for 20 minutes, or until they are crisp and golden. The puffs may be stored overnight in an airtight container.