Add all of the ingredients for the soup to the Instant Pot and give them a couple of stirs. Secure the lid and set to pressure cook on high for 15 minutes (30 minutes if using frozen chicken).
While the soup is cooking, prepare the dumplings by sifting together the flour, baking powder, and salt into a medium bowl. Add the nutmeg and black pepper and whisk to evenly combine. Whisk the eggs and milk together in a separate bowl, then slowly add the wet ingredients to the dry ingredients, stirring as you go. Continue to stir until no dry clumps remain, then set the dough aside until ready to use.
Once the timer on the Instant Pot goes off, carefully open the vent to quickly release the pressure. When it is safe to remove the lid, carefully do so. Use a ladle and a carving fork to shred the meat and to fish the bones, cartilage and skin out of the soup. This will take about 10 minutes, but take your time getting these things out. It is never fun to bite into a mouthful of cartilage or worse, a bone. Although this step may be a bit tedious, don’t be tempted to use boneless chicken. The skin, bones, and cartilage are what give the broth its flavor! (See the note below if you still want to use boneless chicken.)
Cancel the ‘warm’ setting and set the Instant Pot to the ‘soup / stew’ setting, then add the dumplings to the stew. I use two teaspoons to do this; one to scoop up about 1 teaspoon of dough and the other to slide the dough off into the stew. When you add a dumpling to the stew, immediately dunk it below the surface of the broth. Although the dumplings will float back up, dunking them coats them with fat and keeps them from sticking together. Continue until all of the dough is used up, varying the dumpling size a bit to make it interesting. The dumplings will double in size as they cook, so don’t make them any bigger than 1 teaspoon (or they may not cook all the way through). Once all of the dumplings are in the stew, continue to cook the stew uncovered for another 15 minutes. It will begin to boil, this is ok.
When ready to serve the soup, cancel all settings on the Instant Pot and allow the stew to cool slightly because it will be very hot by this point. Use a large ladle to serve it into bowls and garnish with fresh parsley, a sprinkle of sea salt and a grind of black pepper.
Note: Should you decide to use boneless chicken, dark meat will give you the best result that is most similar to homemade stock. If you prefer using white meat, add some olive oil or butter to the soup in step one to prevent your broth from falling flat.