Using a pestle and mortar, combine the salt, sugar, pepper, garlic and orange zest. Smash together until the mixture forms a thick paste.
Dry the duck legs with paper towel, then pat the paste over them, and place in the fridge, uncovered, overnight.
When you are ready to cook the duck, select Sauté, Normal/Medium and set the time to 10 Minutes.
Wipe the cure from the legs with a paper towel, then add a little oil to the inner pot and place the legs in skin side down until they turn golden and the fat has started to render off.
After about 5 Minutes, flip them over and brown the other side. (If necessary, do this in batches.)
Press cancel and flip the duck legs over again. With the 3-4 tbsp of rendered duck fat still in the pot, secure the lid and let the duck sit in the sealed pot for 5 Minutes to trap in moisture.
Pressure Cook on High for 40 Minutes. When the time is up, carefully quick release the pressure.
While the duck cooks, peel and segment your orange. Set the segments aside for the salad, then squeeze the remaining orange to release the juice into a bowl, to use later.
Remove the duck from the inner pot and set aside. Scrape the bottom of the pan to release all the sticky crispy bits into the pan juices, then drain the liquid into a jar or jug to allow the fat and gravy to separate. Once separated, pour off as much fat as possible and set to one side.
Toss your cooked grains with 1 tsp of the duck fat, then place into the air fryer basket. Select Air Fry and set the time for 8 minutes and set the temperature to 190°C / 375°F and press Start (no need to wait for any preheating).
Once the grains are brown and crisp, place them into a serving bowl and put the duck into the fryer basket and put on the Air fryer lid. Select Air Fry again, and the time to 7 Minutes and temperature to 190°C / 375°F and press Start While the duck crisps, toss the orange segments and rocket through the grains and combine the reserved meat juices with the orange juice.
Once the duck is crisped and golden, plate it up alongside the salad. Drizzle over your orange sauce and serve immediately.