Heat a large, heavy-bottomed pot with the oil over medium- high heat.
Add the sweet potato and onion and cook for about 5 minutes, until the onion is softened.
Add the garlic, chili powder, chipotle, cumin, and salt. Stir to combine.
Add the vegetable stock, tomatoes, black beans, and quinoa. Stir everything together and bring the mixture to a boil.
Once boiling, cover the pot and reduce the heat to maintain a gentle simmer. Cook for 15-25 minutes until the quinoa is fully cooked and the sweet potatoes are soft. The mixture should be thick like a chili.
Remove the pot from the heat and add the lime juice. Season with salt as needed.
Garnish with avocado, cilantro, cheese, cilantro lime yogurt, salsa verde, and/or Greek yogurt before serving.