Alternate the cubes of duck and slices of fig onto the skewers until you have three pieces of each on each skewer.
Pour the orange juice and vinegar into a small saucepan and reduce over a high heat by two thirds or until slightly thickened. When the juice has cooled pour over the pinchos and leave to marinade in the fridge for a couple of hours.
Heat a grill pan or barbecue to maximum heat; remove the skewers from the fridge and wipe of any excess marinade. Season with salt and pepper and lay on the grill.
Cook for 2 minutes until the meat is lightly charred and caramelized and then turn over and repeat for 3 minutes. Turn down the heat or move the grill up above the flames and cook for 2 minutes or so until the duck is cooked pink- when prodded with a finger there should be a slight bounce to the meat.
Place the skewers in a warm spot to rest for a couple of minutes and pour over the remaining marinade.