Heat a large heavy bottom pot with the oil over medium high heat.
Add the sweet potato and onion and cook for about 5 minutes, until the onion if softened.
Add the garlic, chili powder, chipotle, cumin and salt and stir to combine.
Add the stock, tomatoes, black beans and quinoa and bring the mixture to a boil. Stir everything to combine.
Cover the pot and reduce the heat to maintain a gentle simmer.
Cook for 10-15 minutes until the quinoa is fully cooked and the sweet potatoes are soft.
Add the lime juice and remove the pot from the heat. Season with salt as needed.
Garnish with avocado, cilantro, crema or cheese before serving.