Steamed Flounder with Hot Balsamic Sauce

Rinse fillets and pat dry with paper towels. Place in a Chinese steamer or a wire rack (one used for cooling cakes) that is large enough to hold fillets in a single layer. Lay a double sheet of heavy-duty foil over rack, folding edges back several times to form a ridge around the fish. Cut several slashes in foil to allow juices to escape. Place rack over a large skillet filled with 1-inch water. Cover fish with more foil and steam until done.

Meanwhile, lightly coat a small nonstick skillet with cooking spray. When fish is done, transfer to heated serving platter. Mix together vinegar and soy sauce. Add olive oil to skillet and place over high heat. When oil smokes, add vinegar-soy sauce mixture, then immediately remove skillet from stove. Pour sauce over fish and sprinkle with scallions.