1. Heat oven to 350 degree F.
2. For the zucchini relish, place onion in small strainer and rinse under cold running water. Drain. Transfer to medium bowl. Stir in zucchini, carrots, jalapeno, white wine vinegar, olive oil, sugar and 1/4 teaspoon salt until well combined. Set aside.
3. Cut each flounder fillet crosswise in half. Combine 1/2 teaspoon salt, pepper and cumin in a cup. Sprinkle on both sides of fish. Heat two large nonstick, ovenproof skillets over medium-high heat for 2 minutes. Add 2 teaspoons oil to each skillet and swirl to coat. Place 4 pieces of flounder, skinned side down, in each skillet. Cook 3 minutes; transfer skillets to oven. Bake fish just until cooked through, 4 to 5 minutes.
4. Carefully transfer 2 pieces of fish with flexible metal spatula to 4 dinner plates. Serve with Zucchini Relish and tomato wedges, if desired. Makes 4 servings.