Béarnaise sauce is a variation on Hollandaise sauce, one of the five mother sauces.

Béarnaise Sauce

3 tablespoons tarragon or white wine vinegar or white wine
2 teaspoons chopped onion
1 teaspoon tarragon leaves, crushed
1/4 teaspoon ground pepper
3/4 cup Hollandaise Sauce

1. In small saucepan, bring vinegar, onion and seasonings to boiling. Reduce heat and simmer, uncovered, until almost all liquid has evaporated. Stir hot mixture into Hollandaise sauce. Cover and refrigerate if not using immediately.

Makes about 3/4 cup.

Recipe provided courtesy of the American Egg Board.