Sear 14 oz lamb shank for about 2-3 minutes on each side until browned.
Add 5 cups of water, 2 cups cooked white navy beans, 1 medium yellow onion (diced), 2 tomatoes (diced), 1 medium yellow potato (diced), 2 tsp turmeric, 2 tbsp apple cider vinegar, 1 tbsp tomato paste, and 2 tsp salt to the pot.
Close the Instant Pot lid and set the valve to sealing.
Select the Pressure Cook (or Manual) setting and cook on high pressure for 35 minutes.
Once the cooking time is up, allow for a natural pressure release for 10 minutes, then carefully switch the valve to venting to release any remaining pressure.
Open the lid and remove the lamb shank. Shred the meat with a fork.
Notes
Leftovers: Store in an airtight container in the fridge for up to 3 days. Freeze for up to 2 months.
No lamb: Replace the lamb with chuck roast or chicken thighs