Combine beef, tomatoes, bell pepper (red or green), celery, potato, carrot, onion, sweet potato, salt and tomato paste in 5-qt saucepan; mix well. Bring to a boil; reduce heat. Simmer, covered, for 1 hour, adding water if necessary. Stir in cayenne pepper and peanut butter. Simmer for 1 hour longer or until vegetables and beef are tender. Add peas. Simmer for 5 minutes. Ladle onto large platter. Garnish with bell pepper slices and parsley. Serve over rice.