Put the chicken stock in a large pan and bring to a boil. Add the spaghetti to the chicken broth and cook until al dente. Do not overcook.
When the spaghetti is cooked, add to the pot thechicken, mushroom soup, 1 1/2 cups cheese, green peppers, red peppers, onions, salt, cayenne, and sprinkle with salt and pepper.
Place the mixture in a casserole pan and top with the remaining 1 cup cheese.
Bake about 45 minutes, or until bubbly. (If the cheese on top starts to get too brown, cover with foil).
Notes
Instead of baking, you can cover and freeze the pan up to 6 months OR cover and refrigerate up to 2 days before cooking.