Chicken Spaghetti Casserole

Preheat oven to 350 degrees. In a large pot, bring salted water to boil and add spaghetti. Boil for 1 minute, stirring occasionaly to keep from sticking together then turn off heat. Stir occasionaly while cooling down (about 5 minutes) and drain into colander. Put empty pot back on low burner and add 1 stick butter and onions. Saute onions to half translucent and add green bell peppers. Saute until onions are translucent and remove from heat. The green peppers will be half cooked. Add the rest of the ingredients execpt for the spagnetti and mix well. You should have a thick gravy consistancy. In a large mixing bowl, put in spaghetti and what's in the pot and mix well. Grease or spray a 4.5 qt. (10x16) pyrex casserole dish and add mixture. Level mix to make sure all spaghetti is submerged. Sprinkle mozzarella over top and bake for 45 minutes or until cheese is starting to brown. Remove from oven and let rest for 5 to 10 minutes before serving.