1/2 c. (1 stick) butter
4 egg yolks
2 tbsp. fresh lemon juice
1/4 c. boiling water
1/4 tsp. salt

Cream butter in a small mixing bowl, at high speed until light and fluffy. Add egg yolks, one at a time, beating very thoroughly after each addition. Continue beating at high speed and very gradually add lemon juice, then water and salt. (Mixture will thin out.) Transfer to a heavy saucepan. Cook over low heat; stirring constantly, until thickened. Serve immediately or place over warm water until serving time. Serve on broccoli or asparagus.

VARIATION: Bernaise Sauce: Reduce lemon juice to 1 1/2 tablespoons. When sauce has thickened, add 1 tablespoon tarragon vinegar, 1 teaspoon chopped parsley, 1/2 teaspoon onion juice and 1/4 teaspoon leaf tarragon. Serve on beef or poached eggs.