Preheat the oven to 375°. In a medium pot over medium heat, add the water, milk, butter, sugar, and salt. Bring to a slow boil.
Then, add the flour and stir with a wooden spoon until the mixture comes together about 5 minutes. Keep mixing until the dough get drier and pull away from the sides of the pot, about 2 minutes.
Take the pan off the heat and then whip slowly adding the eggs one at a time. Be sure that each egg is fully incorporated before adding the next. Once the eggs are incorporated, mix in the parmesan and season with pepper.
Using a piping bag, make 7-inch lines of dough leaving about 1 inch in between. Pat down any sharp edges. Place in the center of the oven and bake for 10 minutes. Rotate the tray and bake for a further 10 minutes until they are golden brown. Allow to cool before filling and serving.
Fill with your choice of meats, cheeses, and veggies. I love the combo of cured Parma ham and arugula, rosemary ham with cheddar and butter lettuce, or the classic tomato and mozzarella with arugula.