In a large Dutch oven or pot, heat the olive oil over medium high heat.
Add the onion and sweet potato and sautee about five minute or until onion is soft.
Add the garlic, chili powder, cumin, and salt. Sautee another 30 seconds.
Add the broth and bring to a boil. Reduce heat to a simmer, cook for 10-15 minutes until sweet potatoes are fork tender.
Stir in the black beans, diced tomatoes, and lime juice. Add salt and pepper to taste. Serve and top with your favorite toppings. Store leftovers in the refrigerator in an airtight container.