Prep Ingredients: Peel and dice the sweet potatoes, chop the onion and bell peppers, and mince the garlic. Drain and rinse the black beans.

Sauté Vegetables (Optional): Heat oil in a skillet; sauté onion for 5 minutes, then add garlic and bell peppers, cooking for 3 more minutes. Stir in spices and toast for one minute.

Combine Ingredients: Transfer sautéed vegetables to the slow cooker, add sweet potatoes, black beans, and diced tomatoes, then stir well to combine.

Add Liquid: Pour in vegetable broth or liquid from tomatoes, stir to mix, and achieve desired consistency.

Cook: Cover slow cooker and set it to Low for 6-8 hours or High for 3-4 hours, stirring occasionally.

Season: Once done, taste and adjust seasoning with salt and pepper, and add crushed red pepper flakes if desired.

Serve: Ladle chili into bowls and garnish with toppings like avocado, cilantro, or tortilla chips.