There are several ways of making Bearnaise sauce. This is one very simple rule: Bring to the boil two tablespoons each of vinegar and water. Simmer in it for ten minutes a slice of onion. Take out the onion and add the yolks of three eggs beaten very light. Take from the fire, add salt and pepper to season, and four tablespoons of butter beaten to a cream, and added slowly. Quick Bearnaise Sauce.–Beat the yolks of four eggs with four tablespoons of oil and four of water. Add a cup of boiling water and cook slowly until thick and smooth. Take from the fire, and add minced onion, capers, olives, pickles, and parsley and a little tarragon vinegar.