Ingredients:
16 oz elbow macaroni (or similar)
5-6 oz Extra Sharp Cheddar, cut into small pieces
6 slices American cheese, cut in half
3 T Grated Parmesan
1/3 cup low-fat milk
1/3 cup non-fat Greek yogurt
Directions:
Preheat oven to 425 degrees.
Cook macaroni according to package.
Drain pasta and return to pot. Stir in milk, yogurt, grated Parmesan, cheddar and half of the American cheese.
Transfer pasta to 9"x13" glass baking dish. Cover with remaining cheese slices.
Bake for 20 minutes, or until top starts to brown.
You can use whatever cheese your heart desires. This is what I happened to have on hand, and it turned out great. I was very impressed with how light and creamy the yogurt made this. Butter tends to leave baked mac and cheese greasy and I didn't find that at all with this substitution.