For meat sauce: In a large skillet, cook ground beef, 1 cup chopped onion and garlic until meat is brown and onion is tender; drain fat. Stir in undrained tomatoes, chili peppers, chili powder, 1 tablespoon mustard, sugar, paprika, Worcestershire sauce, cumin, celery seeds, salt and black pepper. Bring to boiling; reduce heat. Simmer, covered, for 20 minutes.

Add frankfurters to skillet. Simmer, covered, for 10 minutes more or until frankfurters are heated through. Remove frankfurters from meat sauce.

To serve, place frankfurters in split buns. Top each with about 1/4 cup of the meat sauce. Serve with cheddar cheese and additional onion and mustard. Makes 10 servings.

Brown ground beef mixture as above; drain off fat. Transfer mixture to a 2 1/2- to 3 1/2-quart slow cooker. Add the remaining sauce ingredients. Cover and cook on high-heat setting for 2 hours or low-heat setting for 4 hours. Add the frankfurters to the slow cooker. Cover tightly; cook 30 minutes more or until frankfurters are hot. Serve as above or turn heat to low or warm and let stand up to 1 hour.