Take your onion and peel it and then mince it into small pieces. Take your garlic cloves and also peel and finely mince those into small pieces.
Take your Instant Pot and put it onto SAUTE mode. Add 2 Tbsp of butter and let melt almost completely, then add your onions and saute for 3-4 minutes, stirring frequently.
Add the garlic, then stir for 1 minute.
Add the arborio rice and cook for 2-3 minutes, stirring frequently.
Add the white wine to the pot and stir to deglaze, scraping the bottom of the pot to make sure nothing is stuck. Hit the CANCEL button on the Instant Pot.
Add the chicken or vegetable stock, dried oregano, salt, and pepper. Stir to combine everything.
Put the lid on the Instant Pot and make sure the valve is sealed. Set the Instant Pot on MANUAL mode for 5 minutes. The Instant Pot will come to pressure (takes around 10 minutes), then start counting down the 5 minutes.
After the Instant Pot is done and beeps, QUICK RELEASE the steam and then remove the lid.
Add the grated parmesan, 4 Tbsp butter, lemon zest, lemon juice, and frozen peas and stir to combine for about 1 minute.
Plate and enjoy. Top with more grated parmesan cheese, if desired.