In a cold crockpot, stir together rice, chicken broth, zucchini, red peppers, green peppers, red onion, carrot, black beans, cumin, 1/2 cup enchilada sauce and salt and pepper. Top with chicken, more salt and pepper. Pour over another 1/2 cup of enchilada sauce, cover and cook on high for 3 hours. Stir after 2 hours and check rice doneness. After 2 hours, adjust cooking time until rice is just finished cooking.