Ingredients

1 stick (1/2 cup) unsalted butter, cut into pieces 

1 teaspoon sugar (optional) 

1/2 teaspoon salt 

1 cup all-purpose flour 

4 large eggs 

Preparation

In a medium saucepan, combine butter, sugar, salt and 1 cup water over medium-high heat. Bring to a boil and immediately remove from heat. Using a wooden spoon, quickly stir in flour until combined.

Return pan to medium-high heat and cook, stirring vigorously, until mixture pulls away from the sides and a film forms on the bottom of the pan, about 3 minutes. Remove from heat and transfer contents to a bowl to cool slightly, about 3 minutes. Add eggs, one at a time, stirring vigorously until incorporated between each addition. Use immediately.