In a large skillet, heat the olive oil over medium heat. Add the diced sweet potatoes and cook for about 5-7 minutes, stirring occasionally, until they start to soften.

Add the diced onion, bell pepper, and minced garlic to the skillet. Cook for another 5 minutes until the vegetables are tender.

Push the vegetables to one side of the skillet and add the ground beef to the empty side. Cook the beef, breaking it apart with a spatula, until browned and cooked through, about 5-7 minutes.

Once the beef is cooked, mix it with the vegetables. Stir in the black beans, diced tomatoes (with their juices), chili powder, cumin, smoked paprika, salt, and pepper.

Reduce the heat to low, cover the skillet, and let it simmer for about 10 minutes, allowing the flavors to meld and the sweet potatoes to cook through.

Taste and adjust seasoning if necessary. Serve hot, garnished with fresh cilantro, and with avocado slices and lime wedges on the side if desired.