Soak kidney beans overnight (or for 12 hours) in 8 cups of water.
Set your Instant Pot to sauté setting for 15 minutes. Add in grape seed oil and sear sausages on both sides until browned. Remove from pot and set aside.
Add in your onion, bell pepper, and celery. Sauté for 5 minutes and add in garlic. Sauté an additional 3 minutes.
Add in turkey leg and necks along with the kidney beans.
Change Instant Pot settings to pressure cook for 1 hour.
Add in remaining seasonings and herbs. Put the lid on top of the pressure cooker and ensure the vent is in a closed position.
When the hour is up, allow the vent to naturally release. Remove bones from turkey leg, adding butter and allowing it to melt. Stir to combine.