1.Saute onion in oil over medium heat for 4-6 minutes or until onions are clear.
2. Add prepared ground beef, salt, pepper, garlic, cumin and chili powder. Cook an additional 4-6 minutes.
3. Stir in ketchup and diced tomatoes. Bring to a boil then reduce heat to simmer.
4. Add cheese before serving.
5. Place franks in bun and top with chili cheese sauce.