Preheat oven to 400F (204C) and line two large baking sheets with parchment paper.
In a medium saucepan over medium heat, bring the water (240ml), salt (1/8 teaspoon), and butter (113g) to a boil. Make sure the butter is fully melted.
Remove from the heat, and add the flour (113g). Use a wooden spoon to hydrate the flour, then place it back over the stove.
Place back on the stove over low heat and keep stirring as you cook until reaches 175F (79C), or until a soft dough forms. If the fat breaks and the dough seems oily, that's ok.
Remove from heat and place in a large bowl or a bowl of a stand mixer. Mix using the paddle attachment or a spoon until cool.
With the mixer on medium-low speed, add the eggs in four additions, one egg at a time, waiting for each egg to completely incorporate before adding the next. Do not add the last (fifth) egg.
Once the last egg has been incorporated stop the mixer and lift the whisk/ paddle attachment. If the dough falls down in a v shape, then it is ready. If not, add the extra egg.
Fill a large piping bag fitted with a round tip, and pipe 2-inch rounds leaving at least 2 inches space between each round.
Bake for 10 minutes at the low (but not the lowest) oven shelf, then reduce the temperature to 375F (190C) and bake for additional 12 minutes.
Do not open the oven door and turn it off, leave the pastries in the oven to cool for 15 minutes.
Crack open the door, and allow the pastries to cool for another 20 minutes.
Remove from the oven, and fill.