Make sauce: In a large skillet heat oil over moderately high heat until hot but not smoking and cook peppers and garlic, stirring, 10 minutes, or until peppers are tender. Transfer pepper mixture to a blender and blend with lemon juice until smooth. Season sauce with salt and pepper and keep warm. Preheat broiler and light brush a small shallow baking pan with oil. Cut four 1/4-inch-thick lengthwise slices from eggplant, reserving remainder for another use. Rinse fish fillets and pat dry. Season fillets with salt and pepper and arrange, skinned side down, in prepared pan. Sprinkle each fillet with 1/2 tablespoon mint. Arrange 2 eggplant slices on each fillet, covering mint completely and overlapping eggplant slices slightly, and brush them lightly with oil. Broil fillets about 4 inches from heat until fillets are just cooked through and eggplant is golden, about 5 minutes. Divide sauce between 2 plates and arrange fillets, brushed with pan juices, on top sauce. Garnish with additional mint. Serves 2. Gourmet September 1994