Place a large pot over medium heat and add the ground beef. Cook until browned, breaking it up with a spoon as it cooks. Drain excess fat if needed.
Add the diced onion and minced garlic to the pot. Cook for 3 minutes until the onion softens.
Stir in the chili powder and ground cumin. Cook for 1 minute to toast the spices.
Add the sweet potato cubes, diced green chiles, and beef broth. Season with salt and black pepper.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 20 to 25 minutes until the sweet potatoes are tender.
Taste and adjust seasoning if needed. Ladle into bowls and top with chopped cilantro before serving.