1 cup elbow macaroni, cooked until just tender and drained
1/2 cup chopped onion
1/4 cup chopped green pepper
1 cup milk
1 can condensed cream of mushroom soup (can use 98% reduced fat)
2 tablespoons margarine
2 tablespoons flour
1/4 cup pimiento (optional)
1 cup frozen mixed vegetables,thawed
1 can flaked white tuna, drained
3 hard boiled eggs, coarsely chopped
salt and pepper, to taste

Serves 4 to 6.

From Southern U.S. Cuisine 

Put margarine in a large skillet over medium heat; add onions and peppers. 
Cook until onions are softened. 
Add flour, milk and soup; stir until thickened. 
Add pimiento, vegetables, tuna, mixed vegetables and cooked macaroni. 
Taste and add salt and pepper. 
Place in a greased 1 1/2-quart casserole or baking dish. Cover with crumbs or other topping and bake in 350° oven for about 30 minutes or until nicely browned.