Pat the fish dry and take out as many bones as possible. Mix the olive oil and lime juice on a large platter. Lay the fish filets in the mixture and turn to coat. Sprinkle with salt, pepper and garlic powder. Let marinate while you prepare the Tomato White Wine Sauce.
Heat a skillet to medium-high. Add a splash of olive oil, then add the onion and let it cook about ten minutes till it softens and becomes translucent, not brown. Add the garlic and jalapeno peppers and cook for about two minutes. Add the tomatoes and the lime zest. Allow it to cook down to where the tomatoes are bright red and the juices reduced. Add the white wine and lime juice, and lower the heat, letting it continue to reduce while the fish cooks.
Heat another large skillet over medium high heat. Add a thin layer of olive oil. Sprinkle the cornmeal onto a large platter and season with salt and pepper. Remove the fish from the marinade and lay each filet into the seasoned cornmeal one at a time. Coat each filet fully just before laying it into the skillet. If you need to cook in batches, keep the cooked filets in a 200°F oven while you finish the rest.
Once the Tomato White Wine Sauce is reduced, add a tablespoon of butter to the sauce to bring it all together and enhance the flavors. Toss the cilantro into the sauce just before serving.
Serve by spooning the Tomato-White Wine Sauce onto a plate and topping it with a fish filet. This is delicious served with buttered rice or orzo and sautéed beans or fresh peas or simply with a green salad.