Add butter to boiling water and bring to vigorous boil.
Add flour all at once and stir over heat until smooth; continue cooking and stirring until mixture leaves the sides of the pan in a mass.
Chill; add unbeaten eggs, one at a time, stirring until smooth after each addition.
The success of these puffs lies in the long patient beating after the addition of each egg.
Beat until the mixture is glossy and again chill.
Drop by spoonfuls on a greased baking sheet or force the batter through pastry tube.
Bake in a hot oven (400 degrees) for 40 minutes.
Do not open the oven door during baking.
As soon as the puffs are taken from the oven, insert a paring knife into each one to allow heated air to escape.
Cool, open on side, fill with whipped cream.