125g Plain flour
1/2 tsp salt
In a sauce pan melt the butter into the water...
add salt and bring to boil
Add the flour all at once and mix in the saucepan cooking out on the heat, stirring constantly till it leaves the sides of the pan.
Allow to cool slightly and add eggs one at a time - ether in a KitchenAid mixer or in a bowl using a wooden spoon. Be sure to mix each egg in well before adding the next. You are looking for a smooth thick batter that holds its shape when dropped off the spoon.