Sam's Club has frozen boneless, skinless flounder fillets for about $10 for 3 pounds. Each fillet is in its own sealed packet.
Defrost fillets in the refrigerator overnight (or if you're in a hurry, place the packets in a sink full of cool water for 10-20 minutes). Do not, under any circumstances, attempt to defrost in the microwave.
Dredge the fillets in flour seasoned with salt and pepper.
Fry the fillets in a mixture of olive oil and butter for about 3 minutes per side, or until golden brown and crispy. Remove the fillets and set aside.
Cut off the heat and add lemon to the oil, butter and fish pan drippings and stir to make a sauce.
To plate, place the fish fillets over a bed of freshly cooked rice, then pour the lemon butter sauce over the top just before serving.