By Lulu Grimes
One of the classic French sauces, hollandaise is made traditionally over a double boiler or, quickly, in a food processor. It can’t be reheated, but can be kept warm over a bain-marie. Serve with asparagus or artichoke, with poached eggs and English muffins to make Eggs Benedict, and with poultry and seafood. You can add freshly chopped herbs at the end of cooking.