In a large saute pan on medium, saute garlic and onion until onion is translusent, approximately 3 minutes.
Add turkey and breaking it up as it cooks. Cook for approximately 5 minutes. Add cumin, chili powder, salt, and pepper and mix well.
Add peppers and saute for another 3 minutes then add sweet potato and chicken stock. Cover and let cook until sweet potato is tender, 6 - 8 minutes.
Add spinach and mix as it cooks down until it's just begun to wilt. Sprinkle cheese on top and cover and let melt for another minute. Serve immediately!