Mac and Cheese with Soubise

Soubise (sue-BEEZ) is a classic French white sauce that deserves a place in the contemporary kitchen. Simple to make with common ingredients, soubise is defined by the onion, this one including both onion and shallot, blended into a béchamel sauce. Good hot or cold, the versatile sauce goes well with roasted or grilled/barbecued meats and with vegetables. Here I turn it into the backdrop for hearty macaroni and cheese, an excellent side dish or vegetarian main course. Escoffier blanched his