In a 6-quart Instant Pot, add the chicken, white/light green scallions, ginger, apple or pear (if using), water, rice, soy sauce, and salt. Stir to combine.
Lock the lid in place and set the vent to “sealing”. Cook on manual pressure (set to high) for 12 minutes. Let it naturally release for 10-15 minutes, then manually release the remaining pressure by moving the valve to “venting”. **Be careful of splatter! The viscous liquid from the rice/collagen will sputter out. Cover loosely with a kitchen towel to prevent a mess!
Transfer the chicken to a cutting board and discard the fruit or just keep it in there (if using). Let the chicken cool for a bit, then remove the chicken skins. You can shred it off the bone on the cutting board and add it back to the soup or just serve the soup with a couple of whole drumsticks.
You can fish out the ginger chunks or just remove it from your bowl, which is a lot easier.
In a medium bowl, whisk together the tahini and sesame oil. Add about ½ cup of broth and whisk until smooth and liquidy, adding more broth if needed. Stir back into the soup along with the greens.
Serve topped with the dark green scallions and any other toppings you’d like.