Heat olive oil in a large skillet over medium heat.
Add diced onions and bell pepper, sauté until soft.
Stir in minced garlic, and sauté for an additional minute.
Add ground beef, season with salt, pepper, chili powder, and cumin.
Cook the beef until browned and cooked through.
Add diced sweet potatoes, cover, and reduce heat to low.
Cook until sweet potatoes are tender, about 15-20 minutes.
Garnish with fresh cilantro before serving.