You need:
3 dl water
100 g butter
2 dl flour
3 eggs
What to do with them?
Put water and butter to boil.
When they do, add flour, mixing well until it forms a smooth ball of dough.
Let cool to lukewarm, then add eggs and beat until smooth.
Take spoonfuls of dough and put in the oven (at 200'C) for about 20 minutes. It's important not to open the oven door while cooking!
The result should look more-or-less like this.