The dough is very similar in its composition and in its making to choux pastry, with the exception of the addition to it of shredded cheese (classically, Gruyère cheese.)
Gougères are usually served room temperature as a side-dish, but they can be served hot as an hors d’œuvre.
They are sometimes confused with profiteroles, but profiteroles can be sweet or savory, depending on their filling, while Gougères are always savoury, and classically, have no filling.
Modern takes on Gougères may use other cheeses, anything from a goat’s cheese to la Vache qui rit, and may even put a filling in them, making them like a cheesy profiterole.
Classically, the dough ends up stiff enough to be formed by hand into balls, which are then cooked in a circle in a pie dish, touching each other. Some variant recipes, however, have the dough more liquidy, so that it needs to be piped. These versions are more likely to have you bake the Gougères spread out on a baking sheet.
Gougères originated in the Burgundy area of France.
New Larousse Gastronomique. Paris: Librairie Larousse. English edition 1977.