Capitalization in food

Solution 1:

There is no more reason to capitalize romesco sauce than there is to capitalize tartar sauce, soy sauce, tomato sauce, cream sauce, picante sauce, diavolo sauce, puttanesca sauce, or rémoulade sauce. It doesn’t work like Caesar salad, French dressing, Dijon mustard, German potato salad, or Italian parsley.

That’s because you only capitalize that first word when it’s already a proper noun or else an adjective derived from a proper noun. Counterexamples in the realm of sauces include Worcestershire sauce, Hollandaise sauce, or Bolognese sauce.

That’s because romesco doesn’t originate as some foreign-looking synonym of Roman. To begin with, it’s either Spanish (and so pronounced /roˈmesko/) or Catalan (and so pronounced /ruˈmɛsku/) in immediate origin, and of course Latin more distantly. The OED defines the word as:

In Spanish (esp. Catalan) cookery: a piquant sauce of red peppers, nuts, garlic, and other ingredients. More fully romesco sauce.

Its etymology is given as:

Origin: Of multiple origins. Partly a borrowing from Spanish. Partly a borrowing from Catalan. Etymons: Spanish romesco; Catalan romesco, romèscol.

Etymology: < Spanish romesco (a1894) and its etymon Catalan romesco (1862 (in a Spanish context) or earlier), variant (with loss of final consonant) of an unattested form *romèscol, ultimately < an unattested post-classical Latin form *remisculum in sense ‘mixture’ ( < classical Latin re- + post-classical Latin misculare meddle v.).

None of its citations capitalize the word. Here are the two most recent ones:

• 1995 R. W. Kern Regions of Spain viii. 168 A unique dish is calçotada (green onions blackened over a fire and served with a spicy nut sauce known as romesco).
• 2006 Decanter June 128/2 Grilled green vegetables and chicken are adorned with crunchy romesco sauce.

Lastly, if you ever use a Romance-style term like:

• French: créme anglaise, sauce hollandaise, à la russe, à la Chateaubriand.
• Spanish: crema catalana, salsa fresca, salsa parisina
• Italian: pizza alla marinara, pesto alla trapanese

Then you are trying to use the original non-English term in English so you should be careful to preserve the original capitalization, which occurs only for proper nouns; there is no concept of proper adjectives there.