One of the trickiest techniques in classical sauce-making is mixing veloute sauce with raw egg yolks. This rich sauce is used to accompany fish, poultry or meat.
Veloute sauce is a classic mixture of butter, flour and stock (fish, poultry or meat) cooked until thickened to a sauce consistency.
In this recipe for a mussel and tomato "stew," the sauce is made from mussel cooking liquid, which gives the sauce its wonderful flavor. Egg yolks processed into the sauce provide the silky texture.
The traditional formula for egg-enriched sauces calls for whisking egg yolks with a small amount of cold liquid (usually cream) to prevent them from curdling as the hot veloute is added. Since egg yolks curdle or cook at about 180 degrees, the mixture is very delicate.
Egg yolks may be placed in the food processor fitted with the metal blade and hot veloute is added while processing. Not only is the mixture perfectly blended without any risk of egg yolks curdling, it is no longer necessary to add cream or any other cold liquid to egg yolks to prevent them from overcooking. Once incorporated into veloute, egg yolks remain stable and the sauce even can be boiled, which explains how mussels can be reheated in the sauce.
MUSSELS WITH TOMATO AND HERBS
3 pounds mussels, rinsed
3/4 cup packed parsley leaves
2 medium cloves garlic, peeled
3 medium onions, peeled and cubed
2 medium celery stalks, cubed
1 tablespoon thyme leaves
1 bay leaf
2 cups dry white wine
1/4 pound butter
1/4 cup unbleached flour
2 medium tomatoes, peeled, seeded and cubed
2 egg yolks
3 to 4 tablespoons lemon juice
Salt, white pepper
Discard broken mussels or those that are open but do not close when shells are pressed together. Place remaining mussels in sink or basin with cold water to cover and scrub with brush or scouring pad to remove dirt or sand. Firmly grasp and pull out fibers protruding from straight side of shell. Discard fibers. Change water and rinse mussels again. Drain, then transfer to large bowl. Cover with cold, wet towel. Refrigerate until cooking time (can refrigerate overnight).
Insert metal blade in dry processor container. Process parsley until minced, then set aside. Mince garlic by adding to machine with motor on. Add onions and celery and chop with 1-second pulses. Transfer contents of container to 4-quart soup kettle. Add 1/4 cup parsley, thyme and bay leaf.
Add mussels and wine to soup kettle. Cover and steam over high heat, shaking pot back and forth several times, until mussels open, about 8 to 10 minutes. Transfer opened mussels to sheet of foil, continue steaming remaining mussels and transfer to foil when open. Fold foil over mussels to keep warm.
Strain liquid from soup kettle into large glass measuring cup. There should be about 2 1/4 cups. Cover and set aside.
Rinse and dry soup kettle. Add butter. When melted, add flour and stir until flour cooks, about 2 minutes. Gradually whisk in mussel liquid and simmer, skimming frequently, until mussel sauce lightly coats spoon, about 3 minutes. Add several dashes cayenne pepper.
Return metal blade to clean processor. Chop tomatoes with half-second pulses, then set aside. Place egg yolks in processor. With motor running, gradually pour 1 cup hot mussel sauce into machine. Return contents of container to kettle. Add chopped tomato, lemon juice, 3/4 teaspoon salt and 1/8 teaspoon white pepper. Heat to simmering and adjust seasoning.
Return mussels and any liquid to kettle. Toss to coat with sauce, sprinkle with remaining parsley and ladle mussels and sauce into soup bowls. Serve immediately. Makes 4 to 6 servings.