How do you say side order in french?

The side order is a completely alien conception to the French. One does not adulterate a flavour by the simultaneous serving of another. Instead of a side salad, the French will serve a separate salad course. You may have seen French menus offering meals with four, five, nine courses; this does not involve eating any more than at an American meal - usually, in fact, less - but eating the dishes consecutively rather than simultaneously. An interesting sidelight on this topic is the American misuse of the term entree to mean a main course, rather than an introduction to the main.