In a large skillet, heat oil over medium-high heat. Add beef and cook until no longer pink. Drain into a colander.
To the same skillet, add green pepper, onion, and carrots. Cook and stir until lightly browned, about 2 minutes. Add garlic and cook 1 minute longer.
Transfer meat, vegetables, and drippings to a 5 or 6-quart slow cooker. If you don’t have a slow cooker, you can use a large pot and keep on low heat.
Stir in tomato sauce, diced tomatoes, green chilies, peanut butter, chili powder, salt, pepper and paprika. Cook, covered, on low heat for 4 hours or until vegetables are tender.
Top with chopped peanuts and shredded cheddar cheese to serve!