1. Cut off duck wings at second joint, remove excess fat and skin, rinse and dry well.
2. Insert chopstick thru neck opening and force along the wing bone under the skin until it protrudes slightly at the second joint.
3. Push other end along other wing so that you end up with a duck that has its arms straight out like a crucifix.
4. Tie a string on to the middle so you can hold the duck and hang it up.
5. Bring 6 cups of water to boil in a wok.
6. Add maltose or honey and stir to dissolve.
7. Add sherry and vinegar.
8. Make a slurry out of the cornstarch and add to wok.
9. When liquid returns to a boil, dip the duck into liquid and spoon liquid over duck.
10. Repeat until duck is thoroughly moistened.
11. Repeat dunking once more.
12. Hang duck by string in a cool airy place with a bowl underneath to catch drips.
13. Leave for 4-6 hours until skin is dry and taught.
14. Put roasting pan on lower oven rack and fill with 2-3 inches of water.
15. Oil rack above pan.
16. Preheat oven to 350.
17. Remove chopstick and string.
18. Put duck on oiled rack in center of oven breast side up.
19. Cook 30 minutes.
20. Turn duck breast down for 45 minutes.
21. Turn breast up for 30 minutes or until skin is dark brown.
22. While duck is cooking make scallion brushes.
23. Trim roots,cut off most of green part, leaving a 3 inch piece.
24. Make several 1 inch lengthwise slits in each end of scallion, put in ice water for 20 minutes, drain and refrigerate.
25. Carve duck and separate meat and skin.
26. Mix hoisin with sesame oil and 1 tbl water.
27. To serve: use scallion brushes to wipe hoisin mixture on to pancakes, add duck skin and meat and scallion, fold one end over and roll up.