PREHEAT OVEN TO 200ºC . Rinse flounder, shrimp and scallops and set aside on a paper towel. Melt butter in a skillet, stir in the flour and cook until tan. Stirring constantly, gradually add the fish stock. Bring to the boil, reduce to a simmer, and cook until reduced by half, stirring as needed. Add the wine and season to taste with salt and pepper. Add a little of the hot sauce to the egg yolks and then stir the yolks back into the sauce. Stir for a moment over low heat without overcooking the yolks. Strain if necessary. You can make 4 individual pouches or one large one. Cut 8 small or 2 large sheets of parchment paper or aluminum foil. Brush half with the oil. Place the fillets side by side in the middle of the large sheet, or one fillet on each small sheet. Place quarter of the shrimp, scallops, mushroom, green onion and parsley on top of each fillet. Spoon the sauce liberally over the seafood and top with the reserved green onion. Top with a similar sheet of parchment paper, securing tightly, so that no juice can escape. May be made ahead to this point and refrigerated. Place the pouches on an oiled baking sheet and bake until the paper browns, about 10 minutes. Serve in the pouch slitting the pouch at the table, or open the pouch and turn onto a plate or the serving platter just before serving. Serve this with boiled rice (See RECIPE).