1. Heat bacon drippings in a large skillet over medium heat. Add onion, and cook, stirring often, 5 minutes. Sprinkle onion with flour, and cook, stirring constantly, 3 minutes. Add tomato and next 3 ingredients. Cook, stirring often, 6 minutes.
2. Add milk, and bring to a light boil; reduce heat to a simmer, and cook, stirring often, 2 minutes. (If gravy becomes too thick, add more milk for desired consistency.)