For Crock-pot: Add onions and peppers to a microwave-safe bowl. Cook in microwave for 3 minutes, to soften a bit. Brown ground beef in a large nonstick pan. Pour into a colander to drain any fat. Add browned meat to crock-pot. Mix in softened bell peppers and onions, tomatoes, beans, tomato sauce, fajita seasonings, cumin, and chili powder. Cover and cook on low heat for 7-8 hours or high heat for 4-5 hours. Time varies depending on your crock-pot.
For Stove-Top: Add onions and peppers to a microwave-safe bowl. Cook in microwave for 3 minutes, to soften a bit. Brown ground beef in a large nonstick pan. Pour into a colander to drain any fat. Add browned meat back to pan Mix in softened bell peppers and onions, tomatoes, beans, tomato sauce, fajita seasonings, cumin, and chili powder. Bring to a boil; reduce heat and simmer, uncovered for 25 minutes.
This chili freezes great. Serve with optional toppings on the side and let everyone customize their own bowl, if desired.