Press SAUTE High on Instant Pot. Add the oil and the butter in the main insert. Add the shallots, sprinkle some salt and cook for about 2 minutes so it softens and just lightly browns. Then, add the garlic and sauté for another minute.
Add the mushrooms and other veggies and continue stirring till mushrooms sizzle and start releasing water and turn darker brown in color.
At this time, scoop out and reserve some of the mushrooms and veggies aside if you want to use them as a topping later. Add in the rice and mix it in with everything in the pot and continue sauté for 1-2 minutes. Next, add in the white wine. Give it a good stir.
Lastly, add in the broth, black pepper and Italian seasoning. Stir well. Adjust the salt. Deglaze bottom of the pot so nothing’s stuck on. Scrap with wooden spatula. This is an important step that ensures you don't get BURN notice on Instant Pot.
Cancel SAUTE function. Secure the lid. Press “Manual” or “Pressure Cook” High Pressure for 6 minutes. After it's done cooking, wait on " keep warm timer " for 10 minutes and then release leftover pressure by moving the valve from SEALING to VENTING. Open the lid.
Add in the grated Parmesan cheese and truffle oil, stir until well combined and transfer to a serving dish. Sprinkle dried or fresh chopped herbs. Garnish with previously set aside sautéed mushrooms and other veggies. Drizzle some truffle oil on top.
Delicious risotto is ready to be devoured. Bon Appetit !