Versatile Sauce Is Quick to Make and Is a Superb Accompaniment

Versatile is the word for Mustard-Mayonnaise, a sauce that belongs in the repertory of every good cook because it takes only five minutes to prepare and can be used in so many different ways.

While the taste of Mustard-Mayonnaise can vary with the type of mustard added to the basic mayonnaise, the sharp, tangy flavor of Dijon mustard is the natural choice.

Dijon Mustard-Mayonnaise makes a superb accompaniment to cold cooked meat, seafood, or vegetables of almost any description. It is also the basic sauce for two famous French salads--Celery Root Remoulade and Mussels With Mustard Sauce--which can be quickly made using the same basic mayonnaise recipe.

About 95 seconds of processing is required to produce perfect Mustard-Mayonnaise. First, egg yolks, lemon juice, salt, pepper and mustard are processed with the metal blade until the mixture becomes fluffy, usually within 30 seconds. Then, with the machine running, oil is added in a slow, steady stream within 60 seconds.

Since a thick mayonnaise is required for both salads, it is important to slowly incorporate oil into the egg yolk mixture. The more slowly the oil is added, the thicker the mayonnaise.

The food processor technique that applies to this sauce is called timing the pour, which means that a second hand on a wristwatch or clock should be used to verify the time it takes to add the oil to the mayonnaise base.

Keep in mind that oil is added very slowly in the first 15 to 20 seconds of processing, or until the mayonnaise takes or begins to thicken. The signal is a slight change in the processing sound. Mustard-Mayonnaise will thicken more quickly than regular mayonnaise, however, because mustard contains a substantial amount of natural vegetable starch.

There is a wide variety of Dijon mustards available in supermarket and specialty food stores. Their flavors can vary substantially in saltiness and sharpness. It is always a good idea to taste the mustard before using it in this sauce and adjust the amount needed in the mayonnaise to suit your taste.

MUSTARD-MAYONNAISE

3 egg yolks

2 tablespoons lemon juice

1/2 teaspoon salt

1/4 teaspoon freshly ground white pepper

Dash cayenne pepper

1/4 cup Dijon mustard, or more to taste

1 1/4 cups mild olive oil or vegetable oil

Insert metal blade in dry food processor container. Add egg yolks, lemon juice, salt, white and cayenne peppers and mustard. Process 30 seconds.

With machine running, pour oil through food chute in thin steady stream within 60 seconds. Clean container side with spatula and process 5 seconds longer. Adjust seasonings to taste and refrigerate until ready to use. Makes 1 1/2 cups.

CELERY ROOT REMOULADE

1 tablespoon lemon juice

2 1/2 pounds celery root, peeled

Mustard-Mayonnaise

1 large head butter lettuce

8 large whole black pitted olives

Place lemon juice in large mixing bowl filled with cold water. Cut celery root in chunks to fit food chute, then place in bowl of water.

Insert medium shredding disc in food processor. Shred pieces of celery root with firm push, emptying processor container as necessary. Mix shredded celery root with Mustard-Mayonnaise. Refrigerate. Serve immediately or cover with plastic wrap and keep refrigerated up to 2 hours until ready to serve. At serving time, spoon celery root onto lettuce leaves and garnish with olives. Makes 8 servings.

MUSSELS WITH MUSTARD SAUCE

3 pounds mussels, rinsed, scrubbed and fibers removed

1 1/2 cups dry white wine

1/2 teaspoon dried thyme leaves

1 small onion, peeled and quartered

Mustard-Mayonnaise

1 large head butter lettuce

Snipped chives

Sliced French bread

Rinse mussels under cold running water and transfer to large saucepan with wine, thyme and onion. Cover and heat to boiling. Shake pan and cook 5 to 6 minutes or until all mussels are open. If necessary, remove open mussels to bowl and continue cooking unopened mussels 5 minutes longer. Discard any that do not open.

Strain and reserve mussel liquid for use as fish stock. Remove mussels from shells. Place in bowl, cover and refrigerate until shortly before serving time.

To serve, toss mussels with Mustard-Mayonnaise. Spoon onto lettuce leaves, garnish with snipped chives and serve with French bread. Makes 8 servings.