Though lately quite fond of experimenting with different marinades on fish steaks (of various kinds), and briefly baking in a preheated 400F/200C oven, I'm unhappy with how wasteful it is to do this on a regular basis. It takes too much energy to preheat the oven for a few minutes of cooking.
Finding something else to bake just after is not always feasible, and one-day-old baked fish is less than palatable.
Substituting by frying in cast iron would be ideal, except for the lingering flavor in the patina, and we're no longer using Teflon-coated pans (out of health concerns) and so that is no longer an option.
What substitutes are there to high-heat baking fish?