Turn on the "Sauté" feature on the Instant Pot.
Sauté the chopped onion, mushrooms, garlic, and oil for about 1-2 minutes.
Add in the broth, rice, rosemary, salt, and pepper.
Place the lid on the Instant Pot and set the valve to "Sealing".
Cook on high pressure for 6 minutes.
Allow the Instant Pot to natural release for another 8 minutes.
Turn the valve to "Venting" to quick release any remaining pressure.
Once the float valve has dropped, remove the lid.
Stir in the peas and parmesan.
Serve and enjoy!
