Heat the olive oil in a large saucepan over medium heat. Add the onion, reduce heat to low and sauté until golden, about 10 minutes. Remove the onions and set aside. Increase the heat to high, add the meat, and cook for about 12 minutes, until lightly browned on all sides.
Return the onions to the pan, add the tomatoes and garlic, and cook until aromatic, 2 min