1/2 cup chopped onion
3 tablespoons butter or 3 tablespoons margarine, melted
2 (10 3/4 ounce) cans cream of chicken soup
2 cups shredded cheddar cheese, divided
1 cup milk
3 1/2 cups chopped cooked chicken
2 1/2 cups cooked macaroni
1/4 cup Ritz cracker crumbs
In a large skillet over med-high heat, saute onions in butter until onions are tender.Add in soup and 1 ½ cups cheese; gradually stir in milk.
Cook over medium heat until cheese melts; stir in chicken and macaroni; taste and adjust seasoning with salt and pepper.
Transfer mixture to a greased 2 ½ quart casserole; sprinkle with cracker crumbs.
Bake in a preheated 350° oven for 30 minutes or until heated through.
Top with remaining ½ cup cheese and bake 5 minutes.