Blend the wine, Worcestershire, lemon juice, and garlic in a broad bowl. Place the tuna steaks in this mixture for about thirty seconds on each side. Shake off excess marinade and set tuna aside.
Strain the excess marinade into a small saucepan and bring to a light boil. Reduce by half and hold.
Place a large black iron skillet over the hottest heat source you have. The pan is ready when the oils that have soaked into the metal have burned off and the surface is smoking.
Combine the Creole seasoning with the salt in a bowl. Sprinkle the Creole seasoning liberally over both sides of the fish. Spoon melted butter over both sides, enough for it to drip a bit.
Place the fish into the hot skillet. WARNING! There is a very good chance that this will flame up briefly. It's a certainty that there will be much smoke. The fish will first stick to the skillet, but after about a minute or so it will break free. Turn it and cook the other side the same way. It should be red in the center.
To make the lemon butter sauce, reduce the marinade by half, then remove from the heat. Whisk in the softened butter a tablespoon at a time to make a creamy-looking sauce.