Basic Cheese Sauce

Source: Just Recipes

2 tb Margarine or butter
2 tb Flour
1/2 ts Salt
1 c Milk
1 c Sharp cheese, grated
pinch Cayenne pepper

In a medium microwavable bowl, place the margarine, flour and salt;
microwave on high for 2 minutes, stirring after 1 minute. Gradually
stir in the milk. Microwave on high for 4-5 minutes, stirring every
minute until sauce is thick and bubbly. Add grated cheese and stir to
blend well. Add pinch of cayenne if desired. For thicker sauce, use 3
Tbsp of flour.