Press the sauté button on the Instant Pot and add the olive oil. Once hot add the lamb shanks and brown them all around. This will take about 10 minutes for a good sear and you can rotate them intermittently. Otherwise you can do this step in a pot or frying pan. Once the shanks are seared set then aside and start cooking the vegetables.

With the shanks set aside and the Instant Pot still set on sauté, add the onions, carrots and celery. Cook for roughly 5 to 7 minutes then add the garlic, cook for a further minute and add the tomato paste.

Add the red wine to deglaze the pot while scraping the bottom and mix. Let it cook for 6 to 8 minutes until the wine has reduced by at least ¾.

Add the stock, fresh herbs, bay leaves, season with salt and pepper to taste.

Return the lamb shanks and fit them in so the liquid covers them (submerged). It might just reach the top but not cover them, that's okay. Close the instant pot.

Press cancel to cancel the sauté setting. Make sure the vent is turned to SEAL and then set the Pressure Cooker to Manuel, high pressure 50 minutes. Done.

When the timer on the cooker goes off to say it's done and the cooking cycle is complete Don't Do Anything. Allow a natural pressure release. This takes about 20 minutes. You will hear the pin drop / the valve drops back into the lid of the pot, the pot is ready to be opened. If you happen to be standing there you'll see and hear the pin drop.

Remove the meat and set aside, cover in aluminum foil to keep warm.Set the pressure cooker to sauté so the remaining sauce can simmer.

Mix the maizena / cornstarch with the water and make a slurry, pour it into the simmering sauce and give it a good stir to dilute the slurry into the sauce without lumps. Let it simmer, a few more whisks or stirring until you have the thickness you want in the gravy.

Pour the gravy over the lamb shanks when serving and serve with mashed potato, a side of greens or your preferred sides and (optional) garnish with fresh thyme.