(Simplified From Gouffe)

Fry or stew half an ounce of shallot or onion chopped, in a dessert-spoonful of vinegar; let it cook until the vinegar is all absorbed - be very careful about this; then put it into three-quarters of a pint of brown sauce (to which you have added a gill of broth or water to allow for the boiling away); add a tablespoonful of chopped cucumber, and one of chopped parsley; cook gently fifteen minutes.