1 Preheat the oven to its lowest temperature.
2 Wash the duck breast, dab dry and make diamond-shape incisions in the skin. Season with salt and pepper and place in a hot frying pan skin-side down for about 5 minutes until brown. Fry briefly on the other side, then place in the oven on a rack, with a roasting pan underneath for 30 minutes until medium rare.
3 In the meantime wash and clean the pak choi and cut the leaves and stalk into strips. Peel the carrots and cut into strips. Wash the celery and cut into strips. Blanch the vegetables in boiling, salted water. Remove and drain well. Briefly place the wan tan sheets into the water and drain well.
4 Cut the duck breast into thin strips and place on the wan tan sheets, together with the vegetables. Roll up and serve with a dip.