Chop up fine lean ham and onion, add a little celery, the stalks of parsley, clove, pepper, and bay-leaf.
Pour over these ingredients vinegar. Cover the saucepan and allow it to boil until it has consumed one-half.
Put into another saucepan bouillon. Allow it to boil, and then thicken with potato flour which has been diluted in a little cold water. Drop this, little by little, into the saucepan until you have gained the required thickness for the sauce. Then pour in the boiled vinegar, passing it through cheese-cloth.
Mix well together and add French mustard, some capers, and some chopped-up pickles.
Serve hot with meats or tongue. The pepper should predominate in this sauce.