- Cook macaroni according to package directions; drain.
- In saucepan, melt 6 tb butter or margarine over low heat.
- Blend in flour and 3/4 ts salt.
- Add milk all at once.
- Cook quickly, stirring constantly, until mixture thickens and bubbles.
- Add cheese; stir until cheese is melted.
- Stir in tuna, diced apples and drained macaroni; turn into 12x7x2 inch baking dish.
- Combine melted butter and crumbs.
- Sprinkle on top of casserole.
- Bake in 350 oven for 30 minutes, or until apples are tender.