Brown sugar with mustard, salt, pepper, oil and vinegar. A sauce for brawn, specifically Oxford Brawn, or game (Acton 1845).

Original Receipt from 'Modern Cookery for Private Families' by Eliza Acton (Acton 1845);

OXFORD BRAWN SAUCE.
Mingle thoroughly a tablespoonful of brown sugar with a tea-spoonful of made mustard, a third as much of salt, some pepper, from three to four tablespoonsful of very fine salad-oil, and two of strong vinegar; or apportion the same ingredients otherwise to the taste.