Preheat the oven to 400 degrees.
In a medium saucepan bring the water and butter to a slow boil and boil until the butter is melted.
Reduce the heat to low and add in the flour and salt. Stir continuously until the mixture pulls away from the sides of the pan and forms a ball. Remove from the heat.
Add eggs one at a time and vigorously beat well with a fork. Mix in each egg until it is completely incorporated with flour, water and butter mixture. It should have a glossy look to it. Repeat this process until all eggs have been added. This process can also be done using a mixing bowl and a mixer.
Using a tablespoon or a medium cookie scoop, drop the pastry onto a parchment lined baking sheet or in a greased muffin tin making to 12 pastry shells. They can also be pipped using a piping bag or a resealable bag with the end snipped off.
Bake for 25-35 minutes or until they are golden brown. If they are undercooked, they will collapse and fall in. It's better to overcook them than under cook. If you're unsure if they ready, bake them for 1-2 more minutes and recheck them. When the pastry is done, turn the oven off, and open the oven door a bit, and let the pastry cool in the oven for 7-10 minutes.
Remove from the oven and let cool before removing from the pan.
The pastry needs to be room temperature before filling.