Thaw fish, if frozen. Rinse fish and pat dry with paper towels. Measure thickness of fish. Spray a shallow baking pan with nonstick spray coating; set aside.
Stir together bread crumbs, cornmeal, and lemon-pepper seasoning. Add oil, tossing to combine. Brush one side of each fish fillet with egg white, then dip in bread crumb mixture. Place fish fillets, crumb sides up, in prepared pan.
Bake, uncovered, in a 500 degree F. oven for 6 to 8 minutes for each 1/2-inch thickness of fish or until fish flakes easily when tested with a fork. If desired, serve with tomato slices and garnish with parsley. Makes 4 servings.