1. Preheat oven to 350 degrees.2. Heat a large oven-safe skillet, preferably cast-iron, over medium-high heat. Add the ground beef and cook for five minutes, breaking it apart with a wooden spoon or spatula.
3. Use a colander over the sink to drain the liquid from the ground beef then return it to the skillet over medium-high heat. Add the onion, garlic, oregano, cumin, salt, and black pepper and cook for another minute.