In a large skillet over medium heat, brown the ground beef until fully cooked. Drain excess fat.
Add the chopped onion, garlic, and bell pepper to the skillet and sauté for about 5 minutes, or until the vegetables are tender.
In the crockpot, combine the browned meat and vegetables with the diced tomatoes, kidney beans, black beans, tomato sauce, chili powder, cumin, paprika, salt, and pepper.
Add the water (or beef broth) to the mixture. Stir well to combine all ingredients.
Cover the crockpot and set it to low heat. Cook for 6 hours, stirring occasionally if possible.
After cooking, taste and adjust seasoning if needed. Serve hot and garnish with optional toppings if desired.
For a vegetarian version, substitute the ground beef with 1 cup of chopped mushrooms or additional beans.
Feel free to adjust the level of spiciness by adding chopped jalapeños or a pinch of cayenne pepper.
This chili can be refrigerated for up to 4 days, or frozen for later use. Just reheat in the microwave or on the stovetop.