2 bunches (3/4 to 1 lb. total) watercress, washed and crisped
3/4 lb. mushrooms, sliced
1 (3 1/2 oz.) can pitted ripe olives, drained
18 cherry tomatoes, halved
1 egg yolk
1/4 c. lemon juice
1/2 tsp. sugar
1/2 tsp. dry basil
1/4 tsp. salt
1/4 tsp. ground nutmeg
1/8 tsp. white pepper
1/2 c. salad oil

Remove and discard coarse watercress stems (you should have about 1 1/2 quarts).

In a large bowl, combine watercress, mushrooms, olives and tomatoes. Cover and refrigerate for 2-4 hours.

In a blender or food processor, combine egg yolk, lemon juice, sugar, basil, salt, nutmeg and pepper; whirl until smooth. With motor running, slowly pour in oil and whirl until thickened.

If made ahead, cover and refrigerate for at least 2 hours or up to 4 hours. Arrange salad on individual plates and drizzle with dressing. Serve immediately. Makes 6 servings.