Set the instant pot to the "saute" option and press "start"
While the pot is preheating, season the meat with salt and pepper then dredge the shanks in flour
Add 2-3 tbsp of butter and wait until it melts then sear the shanks for 2-3 minutes for each side
In the meantime prepare the veggies. Peel and dice the carrots, celery, onion, and garlic. You can use one unpeeled garlic head for extra flavor
Use tongs to remove the shanks from the instant pot and place it on a separate plate
Add the diced veggies to the pot, in the same grease that the meat was cooked
Season the vegetables with salt, pepper, paprika thyme, and add some bay leaves to it. Cook it for about 7-10 minutes without a lid and to stir occasionally
Top the veggies with the Osso Buco's and pour in the beef broth
Seal the pot with the lid, set the "pressure cooking" program for 25 minutes, and press the "start" button
When the time expires, release the steam and open the lid
Serve with gremolata