With spaghetti and mushroom sauce, and light and dark meat chicken with bell peppers, Ree Drummond's casserole is like two meals in one. Cooking the spaghetti in the same liquid as the chicken infuses it with flavor, and the Cheddar thickens the sauce so it coats each piece of meat.
Bring a large pot of water to a boil. Add the chicken pieces to the boiling water and boil for a few minutes, then return the heat to medium-low and simmer, 30 to 45 minutes.
Remove the chicken and 2 cups of the chicken cooking broth from the pot. When the chicken is cool, remove the skin and pick out the meat (a mix of dark and white) to make 2 generous cups.
Cook the spaghetti in the same chicken cooking broth until al dente. Do not overcook. When the spaghetti is cooked, combine with the chicken, mushroom soup, 1 1/2 cups cheese, the green peppers, red peppers, onions, seasoned salt, cayenne, and sprinkle with salt and pepper. Stir in 1 cup of the reserved chicken cooking broth, adding an additional cup if needed.
Place the mixture in a casserole pan and top with the remaining 1 cup cheese. Cover and freeze up to 6 months, cover and refrigerate up to 2 days or bake immediately until bubbly, about 45 minutes. (If the cheese on top starts to get too cooked, cover with foil).