Peel and dice the sweet potatoes into uniform ½-inch cubes for even cooking.

Heat 1 tablespoon of olive oil in a 12-inch skillet over medium heat. Add the ground beef, breaking it apart with a wooden spoon, and cook for 5-7 minutes until browned with no pink remaining. Season with salt and pepper. If using beef fattier than 85/15, drain excess grease. Transfer beef to a plate and set aside.

Add the remaining tablespoon of olive oil to the same skillet. Add the diced onion and sauté for 2-3 minutes until softened and translucent. Add the minced garlic and cook for 30 seconds until fragrant, stirring constantly to prevent burning.

Add the diced sweet potatoes to the skillet and cook for about 10 minutes, stirring every 2-3 minutes. The sweet potatoes should be fork-tender around the edges and starting to caramelize slightly. Sprinkle the chili powder and cumin over the sweet potatoes and stir well to coat everything evenly.

Stir in the diced bell peppers, black beans, and corn. Cook for another 5-7 minutes, stirring occasionally, until the sweet potatoes pierce easily with a fork throughout and the peppers have softened while keeping a slight crisp texture.

Return the cooked ground beef to the skillet and mix everything together thoroughly. Cook for an additional 2-3 minutes to heat through and let the flavors meld. Taste and adjust seasoning with salt and pepper if needed. Garnish with fresh cilantro before serving.