In a large skillet over medium heat, brown the ground beef with the chopped onion. Cook until the beef is no longer pink and the onion is translucent, stirring frequently.
Add the minced garlic and cook for another minute. Drain well.
Combine the ground beef mixture with the bell pepper, celery, tomatoes, tomato sauce, drained beans, and seasonings. Transfer to the crockery insert of a slow cooker.
Cover and cook for 5 to 7 hours on low, or until done.
Taste and adjust seasonings, adding salt, black pepper, and cayenne pepper, as needed.