Place the turkey carcass and water in a Dutch oven or large soup kettle; bring to a boil. Reduce heat; cover and simmer for 1-1/2 hours. Remove carcass; allow to cool. Remove turkey from bones and cut into bite-size pieces; set aside.
Strain broth. Add carrots, celery, onion and bouillon; bring to a boil. Reduce heat; cover and simmer for 30 minutes. Add the tomatoes, peas, rice, spinach, salt if desired, pepper, marjoram, thyme and reserved turkey. Return to a boil; cook, uncovered, for 20 minutes or until rice is tender. Yield: 22 servings (5-1/2 quarts).