Heat olive oil in a large skillet over medium heat.
Add the diced onion and bell pepper to the skillet; cook until softened, about 5 minutes.
Stir in the minced garlic, chili powder, and cumin. Cook for 1-2 minutes until fragrant.
Add the diced sweet potatoes; stir well to coat.
Pour in the vegetable broth and bring to a simmer.
Cover and cook for about 10-15 minutes, or until sweet potatoes are tender.
Stir in the uncooked brown rice and black beans; mix well.
Cover again and cook for an additional 30-35 minutes, or until rice is cooked through and absorbs the liquid.
Season with salt to taste and garnish with fresh cilantro before serving.