Place the stainless steel pot in the Instant Pot. Press the “Saute” button until it’s on “More”. Add the butter.
When the butter is melted, add the onion and salt and cook until the onion is softened, about 3 to 5 minutes, stirring occasionally.
Add the rice and stir for another 2 minutes. If using corn & basil, add with the rice (see note for variations).
Add the wine and cook for about 1 minute, scraping up any rice that has stuck to the bottom of the pot.
Stir in the broth and lock the lid in place. Close the pressure release valve and press the “Pressure Cook” or "Manual" button until it’s on “Normal” and press the “Pressure Level” button until on “High” (High is the default). Press the +/- buttons until it says 00:06 for 6 minutes.
When done, press the “Cancel” button to turn off the Instant Pot and quick release the pressure by opening the pressure release valve, steering clear of the steam.
After the pressure is released and the float valve falls, remove the lid.
Turn the Instant Pot back on “Saute” and stir in the parmesan cheese. Cook for 1-2 minutes until the cheese is melted. If adding shrimp, add with the parmesan and add another 2 minutes to let the residual heat cook the shrimp.
Turn off the Instant Pot and serve.