Preheat the oven to 400°F (200°C).
Peel and dice the sweet potatoes into 1-inch cubes.
Toss the diced sweet potatoes with olive oil, chili powder, and cumin, then spread them evenly on a baking sheet.
Roast in the preheated oven for 25-30 minutes, or until tender and golden brown.
While the sweet potatoes are roasting, prepare the vegetables by dicing the red bell pepper and slicing the avocado.
Heat the black beans in a small saucepan over medium heat, seasoning with a pinch of salt if desired.
Once the sweet potatoes are done, remove them from the oven and let them cool slightly.
Assemble your taco bowl by adding a base of roasted sweet potatoes, followed by a generous scoop of black beans and diced red bell pepper.
Top with sliced avocado, fresh cilantro, and lime wedges.