Heat olive oil in a large skillet over medium-high heat. Add ground beef and diced onion, breaking up the beef with a wooden spoon. Season with 1 tablespoon (3 teaspoons) of chili powder, 1 teaspoon of cumin, salt, and pepper. Cook until beef is almost done, about 5-7 minutes. Add garlic and cook for another minute. Transfer to a plate and wipe the skillet clean.

In the same skillet, add diced sweet potatoes, fire-roasted tomatoes, green chiles, water, 2 teaspoons of chili powder, 1 teaspoon cumin, salt, and pepper. Stir, cover with a lid, reduce heat, and simmer for about 20 minutes or until sweet potatoes are tender. Stir occasionally to prevent sticking.

Return the ground beef mixture to the skillet with the sweet potatoes. Stir to combine. Sprinkle shredded cheese on top, cover with the lid, and cook for another minute or until the cheese melts. Garnish with chopped cilantro if desired and serve.