1. Grate zest from lime. Juice lime. Add water to lime juice to equal 1/2 cup. Combine juice, 1/2 teaspoon zest, mustard, soy, cumin and pepper; reserve 2 tablespoons for sauce. Refrigerate turkey with remaining marinade in plastic bag, 15 minutes.
2. Broil turkey on greased broiler rack 3 inches from heat, 3 minutes each side; brush with marinade.
3. Gently heat reserved marinade, sour cream and water in small saucepan. Remove from heat. Stir in cilantro and remaining zest. Spoon over cutlets. Garnish with tomatoes. Makes 4 servings.