Use a cast iron pan to sear the meat, whether pork, beef or poultry. Remove the meat. Add a little oil or butter, and flour. You can add finely minced onion now, and minced garlic. The garlic should be added almost immediately before adding the stock or wine, since it can burn and become bitter if it's heated too much. Stir vigorously over moderate heat to get the flour to moisten and turn golden brown. Add a little wine, stock or broth. You'd think the more wine, the better, but that's not so. It tend to make the gravy a little bitter. Stock or broth is safe. From there, you can add mustard, cream, worchestershire sauce, a touch of soy sauce, or any number of other flavor. Salt carefully. If you want to sweeten, consider something like ketchup, which adds sweetness and other flavors. Stir with a whisk. If things go south, you can strain through a strainer, or whip with a stick blender, but that should not be necessary if you have the flour well mixed with the oil or butter, and you add liquid slowly with constant stirring. Seconds before serving, add a knob of butter and swirl until it's melted.