Chicken Spaghetti Casserole

– 7 oz spaghetti
– 2 cups cooked chicken, cut up into pieces
– 8 ounces shredded cheddar cheese
– 1/2 cup bell peppers (green or red)
– 1 onion, chopped
– 2 cans (10.75-oz) condensed cream of mushroom soup
– 1 cup milk
– 1 tablespoon butter
– Salt and pepper to taste
– 1/2 cup jack cheese
Optional: Add mushrooms or celery

Directions:

1. Preheat oven to 350°F.