Onion Sauce

The onions can be boiled, chopped, and refrigerated up to 2 days ahead. The finished sauce can be made up to 1 day ahead and stored in an airtight container in the refrigerator. Reheat gently over low heat, whisking frequently and adding a splash of milk if needed to restore consistency.

Store leftover sauce in an airtight container in the refrigerator for up to 3 days. Reheat gently in a saucepan over low heat, whisking constantly. The sauce may appear broken when cold but will come together when warmed. Thin with additional milk if it has thickened too much during storage.