Soak the dried northern beans in water for about one hour, then drain.
Chop the leek, onion, and celery into small pieces.
Place the drained beans and all chopped vegetables into the Instant Pot.
Add the ham hocks to the pot and pour in 4-6 cups of water.
Stir in the chicken bouillon, dill, white pepper, and nutmeg.
Seal the lid and set to Pressure Cook on High for 1.5 hours.
Allow a natural pressure release for at least 15 minutes before opening.
Remove the ham hocks, shred the meat, and discard the bones.
Return the shredded ham to the soup and stir thoroughly.
Mash a few beans against the side of the pot to thicken the broth.
Season with salt to taste and serve with warm cornbread.