In a slower cooker, combine the onion, bell pepper, frozen corn, garlic, chili powder, cumin, cocoa, cinnamon, salt and black pepper. Add the tomatoes with liquid, beans, sweet potato, and one cup of water.
Cover and cook until the sweet potatoes are tender and the chili has thickened, on low for 7 to 8 hours or on high for 4 to 5 hours.
Serve this vegetarian chili with sour cream, shredded cheddar cheese, green scallions, and tortilla chips!
Store the leftovers in an airtight container in the refrigerator four days! You can freeze this chili recipe, too.
I like to use a six-quart slow cooker for this recipe because it is the perfect size!