In a large skillet, heat olive oil over medium heat. Add the ground beef and onion and cook, stirring stirring until ground beef is no longer pink and onion is tender. Add the garlic and continue cooking for 1 minute. Add chopped cabbage, tomatoes, tomato sauce, pepper and salt. Bring to a boil. Cover and simmer for 20 to 30 minutes, or until cabbage is tender. Serves 6 to 8, but is delicious next day.