2 cups uncooked macaroni noodles
1 teaspoon onion powder
1/2 teaspoon dry mustard powder
1 can cream of chicken soup
1/2 cup sour cream , regular or light
1/2 cup mayonnaise
1/2 teaspoon pepper
3 cups cheddar cheese
1 cup gruyere cheese (or you can use 4 cups cheddar cheese)
Boil macaroni noodles according to directions to make them very al dente. (I cook them for at least 1 minute less than directed on the bag. Mine boiled for 5 minutes). Drain and rinse under cold water.
Combine all ingredients in the slow cooker and cook on high for 2 hours or low for 3 hours, stirring once or twice.