What Is a Soubise?

Soubise (pronounced "soo-beez") is a rich French onion sauce. It is made by combining the Mother Sauce known as béchamel with cooked onions that have been puréed, and it is typically served with proteins, such as eggs, grilled meat, poultry, or fish.

The French term can also be applied to dishes that come with a soubise sauce, such as "eggs à la soubise."