Soubise Sauce Tomatée

Soubise Sauce Tomatée (tomato-enriched onion sauce) teaches the family logic of classical sauces. The one true thing to know before touching the pan is the proportion: the tomato purée equals exactly one-third the volume of the soubise, giving you three parts soubise to one part tomato. More tomato buries the onion; less leaves its sweetness unchecked.

The original entry assumed a saucier had already prepared the first formula of Soubise Sauce in brigade quantity, with a very red tomato purée waiting beside it. At home, you begin with six cups of that finished soubise and two cups of concentrated purée. The separate station and holding pots are scaffolding and can go; the finished soubise, the deep colour of the tomato, and the three-to-one proportion are the dish and must stay. One cook, one stove, one evening.

When it is right, the sauce is smooth and glossy, warm brick-rose rather than dull orange, with onion first and tomato arriving as a clean, gently acidic finish. Judge the purée before it meets the soubise. That colour cannot be negotiated afterward.