You may wish to slightly score the duck skin with a sharp knife on a diagonal - do not cut the meat.
In a large bowl combine remaining ingredients and mix well.
Line a bottom of a wok or aluminium pot with a double-folded sheet of aluminium foil that will cover most of the base - this is important to easily remove the burnt caramel rice mixture and save your wok.
Place the mixture in the foil base, spreading evenly across the foil.
Place a wire rack over the mixture, but make sure it's not touching the mixture, about 1-2 inches above is great. Place the duck breasts, skin side up, on the wire rack and cover with a lid.
Place the wok over high heat - make sure your exhaust fan is running on HIGH and open a window or use a barbecue with a wok burner / plate. Heat on high, covered, for 5 minutes at which point the mixture should begin to smoke. Reduce the heat to low then continue to smoke the duck for a further 10-15 minutes for a more medium well result (see note above).
Using tongs, carefully remove the duck from the wire rack and place on a cutting board. Slice thinly (or allow the breasts to cool completely and store in an airtight container in the fridge for 3-4 days - see note above).
Serve over salads or with mandarin-style pancakes, spring onion, cucumber and hoisin sauce.