In a pot bring the water, salt and butter to a boil and then turn the heat to low. Add the flour and work the dough until you have a uniform consistency and it is smooth. Add 1 egg at a time and combined really really well. (Adding the egg with make your dough separate so mix well until the dough has come back together) Continue this until all of the eggs are incorporated. Add grated Parmesan, Gruyere and Chives.