This is one of my favourite street food dishes. In Taiwan they sell this dish in night markets served in newspapers and sprinkled with pickled spicy daikon (white turnip salad). I love serving this as a starter or a lunch for friends. You can prepare most of the ingredients in advance and then fry the duck just before serving.
Place the duck legs in a bowl or plastic food bag together with all the marinade ingredients. Cover with cling film and leave in the fridge to marinate for as long as possible, preferably overnight.
Place all the ingredients for the pickled radish salad in a bowl and combine well. Cover and set aside in the fridge for 1 hour.
Heat the oven to 180ºC/350ºF/gas mark 4. Place the duck legs, skin side up, in a roasting tin and roast for 10 minutes, then turn the oven up to 220ºC/425ºF/gas mark 7 for 5 minutes to cook the meat to well done. Remove from the oven and set aside for 2 minutes to cool slightly.
Slice the duck into bite-sized slices, dust the slices in the flour and coat well.
Heat a wok or pan over a high heat and fill to a quarter of its depth with groundnut oil. Heat the oil to 180ºC/350ºF, or until a cube of bread dropped in turns golden brown in 15 seconds. Place the duck pieces in a spider/scoop, lower into the oil and fry until crispy and golden brown. Remove from the pan and drain on absorbent kitchen paper.
To serve, spoon some pickled radish salad on to each plate and spoon some of the crispy duck slices on top. Sprinkle a pinch of salt and some dried chilli flakes over the duck pieces and serve immediately.
Tip: Ensure your wok is stable before deep-frying.