Mussel Sauce

Scrape eighteen mussels, wash them clean in several waters, and put them into a saucepan with half a gill of water, some vinegar and pepper, but no salt, sprigs of parsley and minced onions; cover the saucepan, set it on the fire, and toss it several times until they open, then take them from their shells, cut off their black parts, and strain the broth after it has well settled; pour off the clear part, leaving the sediment at the bottom, and strain this through a sieve. Put one pint of veloute (No. 415) into a saucepan, also two gills of the mussel broth; reduce, and thicken with four raw egg-yolks, a little nutmeg, half a gill of cream, two ounces of butter, and the juice of a lemon; strain the whole through a tammy (No. 159), and finish by adding a small coffeespoonful of chopped parsley and the eighteen cooked mussels; warm well and serve.