Preheat the oven to 325°F.

Cut off the flap of fat that hangs over the duck’s cavity. Sit the trimmed duck on a rack or slotted tray over a deep roasting pan and roast for 4 hours.

Turn the oven up to 450°F and give a final 30 minutes of intense heat. Or, if it’s easier, just leave the duck in the low oven for 5½ hours. The choice is yours.

Sit the pancakes on the top part of a steamer to cook or simply follow instructions on the package. Pour the sauce in a bowl with a spoon.

Cut the cucumber into matchsticks (like you get in a Chinese restaurant).

Cut the scallions lengthways into short strips (again, like they do in Chinese restaurants).

Carefully take the roasting pan out of the oven and transfer the duck onto a board. When you can handle it comfortably, shred it and set it on the table with the sauce, cucumber, scallion shreds, and pancakes. Wrap the duck meat, topped with the sauce, cucumbers, and scallion, in the pancakes. When the duck fat has cooled a little, pour it into a bowl or jar. It makes great fried potatoes.