Switch on the Instant Pot and set to Saute mode.
Add oil and butter. Once warm, stir in the chopped onion, minced garlic, and celery. Saute for 1 minute.
Add cauliflower, carrot, and potato. Saute for a minute.
Add Bell pepper, Broccoli and peas, followed by the seasoning, Chili flakes, salt and pepper.
Pour in the stock. Mix everything well.
Cover the lid. Set the Instant pot to Manual/Pressure Cooking mode. Cook for 5 minutes. Then let the pressure release naturally for 5 minutes, followed by manual pressure release.
Stir in Heavy cream and Parmesan cheese. Mix until the cheese has melted and mixed well ( Don't overmix else the veggies will become really mushy).
Serve hot with more parmesan cheese sprinkled on top, along with a crusty piece of bread.