Heat olive oil in a medium saucepan, add onion, peppers, garlic and cook for 3~4 minutes or until the onion turns translucent and peppers are tender.
Next add sweet potatoes and cook for 2 minutes. Sir in tomato puree, chili powder, ground cumin, cinnamon and cayenne pepper. Cook for 3~5 minutes.
Add the drained beans and cook for 2~3 minutes.
Next add the drained quinoa, vegetable stock or water, black beans, salt and pepper. Bring the mixture to a boil; lower the heat, cover the pot and cook for 18~20 minutes or until quinoa is cooked through and sweet potato is tender.
If the chili looks too thick, add some water to get the desired consistency. Taste and adjust the seasonings accordingly. Garnish with chopped cilantro and serve hot or warm with toppings of choice.