1Preheat oven to moderate, 180 C.
2Drain plums, reserving 1 tbsp juice. In a medium saucepan, bring combined plums, reserved juice, sugar, soy, five-spice and chilli to boil on medium. Reduce heat to low. Simmer 12 to 15 mins until reduced to 1½ cups. Stir in zest. Transfer to a bowl to cool.
3Place duck meat on an oven tray, cover with foil. Bake 15 mins until warmed through.
4Spread each popiah skin with 1 tbsp plum sauce (see Chef's Tip below). Top with duck, cucumber and onions. Roll up to enclose. Secure with skewers to serve.
*Save time! Replace plum sauce with ready-made hoisin sauce.