Braised Lamb Shanks with Mushrooms and Marsala

INSTRUCTIONS

1. Press Sauté and set to Medium, Normal, or Custom 300°F / 149°C for 20 minutes.
2. As the pot heats, warm the oil in the insert set in a 6- or 8-quart Instant Pot. Add 2 of the shanks and brown them well on all sides, turning occasionally, about 6 minutes. Transfer the shanks to a nearby large bowl, add the remaining 2 shanks and brown them in the same way before getting them into that bowl.
3. Add the onion, carrot, and mushrooms to the pot. Cook, stirring occasionally, until the onion softens, about 3 minutes. Stir in the garlic and salt until aromatic, about 20 seconds.
4. Pour in the Marsala wine and scrape up any browned bits on the bottom of the insert. Stir in the broth, then return the shanks (and any juices in their bowl) to the pot. Turn the shanks to coat them in the sauce, turn off the Sauté function, and lock the lid onto the pot.
5. Max Model: Pressure Cook on Max for 35 minutes with the Keep Warm setting off.
   
   Other Instant Pot models: Pressure Cook on High for 45 minutes with the Keep Warm setting off.
6. When the pot has finished cooking, turn it off and let the pressure return to normal naturally, about 35 minutes. Unlatch the lid and open the cooker. Transfer the shanks to a serving platter or serving plates. Use a flatware tablespoon to skim the surface fat from the liquid in the pot.
7. Press Sauté and set to Medium, Normal, or Custom 300°F / 149°C. Set the time for 5 minutes with the Keep Warm setting off.
8. As the sauce comes to a simmer, whisk the cornstarch and water in a small bowl until smooth. Stir this slurry into the simmering sauce and cook, stirring constantly, until thickened, less than 1 minute. Turn off the Sauté function and use hot pads or silicone baking mitts to transfer the (hot!) insert to a nearby wire rack to stop the cooking. Cool for a couple of minutes, then ladle the hot vegetable sauce over the shanks to serve alongside mashed potatoes. Garnish the plates with fresh sage leaves.