Cheese sauce: Follow key recipe above, except add 1/4 teaspoon dry mustard with seasonings. Blend in 1/2 cup grated cheese. Stir until cheese is melted.
Mushroom sauce: Follow key recipe above, except sauté 1 cup sliced mushrooms and 1 teaspoon grated onion in the butter 5 minutes before adding flour.
Seafood Sauce: Follow key recipe above, except carefully stir into sauce 1/2 to 1 cup cooked shrimp or pieces of other seafood.
Red Sauce: Follow key recipe above except stir in 3 tablespoons tomato puree.
Curry Sauce: Follow key recipe above, except sauté 1/2 teaspoon curry powder in the butter before adding flour and other seasonings.
Egg Sauce: Follow key recipe above, except carefully stir in 2 diced hard-cooked eggs. Season.
Cucumber Sauce: Follow key recipe above, except add 1/2 cup grated or thinly sliced cucumber and a dash cayenne pepper. Simmer 10 minutes.
Dill Sauce: Follow key recipe above, except with the seasonings, add 1 teaspoon minced fresh dill or 1/2 teaspoon dried dill and a dash of nutmeg. Simmer 2 to 3 minutes.