Cut fish into serving size pieces about 1 inch thick.
Soak fish in wine, milk, or lemon juice. Then dust with flour. Followed by a dip in beaten egg.
Heat 2 tablespoons of olive oil in a skillet over medium to high heat and when it is almost smoking add a few pieces of fish. Cook the fish, a few pieces at a time for 2-3 minutes each side. (The fish will finish cooking later.) Remove each piece as it is cooked and set aside.
When all the fish is done, discard the frying fat and wipe the pan out with paper towels. Add remainng 2 tablespoons of oil to pan and over medium-low heat gently cook the onion and garlic until soft but not brown, about 10-15 minutes
Add tomatoes and cook, stirring occasionally, until the tomatoes have given off their juices ad start to thicken, about 10 minutes.
Stir in cumin and cilantro. Taste for seasoning and add salt and pepper if necessary.
Heat oven to 350 degrees. Arrange fish pieces in a shallow baking or gratin dish and cover with sauce. Bake until fish is thoroughly cooked and the sauce is bubbling, about 20 minutes.