For the duck:
1) One day before using the duck, set the duck on a baking rack set over a baking tray and store in the refrigerator uncovered to dry.
2) Preheat griddle to medium heat and set up rotisserie. Season duck with salt and pepper and skewer it onto the rotisserie rod. Place a drip pan under the duck to catch the rendered fat. Once the fat had begun to render off the duck, brush with the hoisin baste every 10 minutes. Cook the duck for 1 to 1 1/2 hours for medium-rare doneness. Remove from the griddle and brush with more of the baste. Let the duck rest for 10 minutes before slicing into thin slices.
3) Drizzle the oranges with peanut oil, Place oranges on the griddle, flesh side down and griddle until golden brown. Remove from the griddle and cut each 1/2 into 1/4's.
4) Drain spring onions. Place hoisin baste, 2 slices of duck and spring onions onto each pancake. Squeeze griddled orange over the meat, roll and eat.
For the hoisin baste:
1) Heat oil in a medium saucepan on side burners or on the grates of the grill. Add onions, garlic and ginger and cook until soft.
2) Add remaining ingredients and season with salt. Cook until the tomatoes cook down, about 25 to 30 minutes.
3) Use an immersion blender to puree or transfer the mixture to a blender and blend until smooth. Return the sauce to the saucepan and cook until thickened, about 15 to 20 minutes. Let cool to room temperature.