Score the skin of the leg with a sharp knife, oil some paper, wrap the
leg up in it, and roast about two hours and a half of a nice yellow
colour; have ready the following sauce: put four tablespoonfuls of
chopped onions into a stewpan, with two ounces of butter, stir over a
moderate fire till the onions are nicely browned, then add three
tablespoonfuls of tarragon vinegar (let it boil), a quart of brown sauce
(No. 1), half a pint of consommé, and a little brown gravy; let it boil
at the corner of the stove about twenty minutes, skim it well, reduce it
till it adheres to the spoon, season with a little cayenne pepper, salt,
and two tablespoonfuls of French mustard; when ready to serve add twenty
small gherkins, twenty pickled mushrooms, twenty small quenelles (No.
120), pour the sauce in the dish, dress the leg upon it, put a paper
frill on the knuckle and serve.