Turn on the saute mode of the instant pot and saute on high to medium mode.
add olive oil in an instant pot pressure cooker.
add the lamb shanks to the pressure cooker.
roast them well for few minutes or until the color changes and appears nicely roasted.
Take them out with the help of tongs.
Into the same oil, add chopped garlic, saute well.
Also, add cinnamon sticks, bay leaf.
Saute few seconds.
add chopped carrots, add chopped onion.
Saute well for few seconds.
add black peppercorns and ginger garlic paste.
saute well.
add black peppercorn powder and salt as per taste.
saute few seconds.
add enough water to dip the shanks.
Place the roasted lamb shanks in the water.
close the lid and turn the steam valve to sealing position.
Cancel the saute mode.
Press the pressure cook mode and set the timer to 1 hour.
Cook for 1 hour until timer goes off.
Natural release the pressure.
Open the lid and serve hot.