Cook the beef – Warm olive oil in a large skillet over medium-high heat. Add the ground beef and diced onion, breaking the meat apart with a wooden spoon. Season with 3 teaspoons of chili powder, 1 teaspoon of cumin, plus salt and pepper. Cook until almost browned, then stir in the garlic and cook for another minute. Remove from the skillet and set aside.

Simmer the sweet potatoes – In the same skillet, combine the sweet potatoes, fire-roasted tomatoes, green chiles, water, the remaining chili powder and cumin, plus a pinch of salt and pepper. Stir everything together, cover with a lid, and reduce the heat. Let it cook gently for about 20 minutes, or until the sweet potatoes are fork-tender.

Combine & melt cheese – Return the cooked beef mixture to the skillet and stir well. Sprinkle shredded cheddar cheese over the top, cover again, and let the cheese melt for 1–2 minutes.

Serve & garnish – Finish with fresh cilantro if desired, then serve hot.