Pre-heat the oven to 400 and line two sheet trays with silicone mats to prepare. First, make the choux pastry dough. Combine the water and cubed butter in a sauce pan and heat it over medium low heat on the stove. When it starts to boil, add in the flour and take it off of the heat while you stir it really well. When it becomes a paste, put it back on the heat and keep stirring for another couple of minutes. It will dry out a little more, cook off the flour and naturally become a ball of dough. Let it cool for a few minutes, then whisk in the eggs really well until the dough is smooth and glossy. Sprinkle a little water on the trays to help steam the dough. Transfer the dough into a piping bag with a plain, 1/2 inch opening and pipe out 3 inch eclairs onto the trays, with 6 on each to give them lots of room to expand.