Add salt and water (use water just enough to barely cover the pasta).
Add frozen corn and close the instant pot with lid in sealing position.
Cook in high pressure for 2 minutes (it will take a few minutes for the pot to come to pressure).
Once the cooking is done, press the cancel button and wait for the instant pot to naturally release the pressure for about 12 minutes.
After this, carefully release any remaining pressure gradually, and open the instant pot.
Add the olive oil, shredded cheese and heavy cream, gently stir in to combine with the pasta evenly.
Serve the easy, creamy and delicious rotini mac and cheese immediately for best results (so the cheese sauce is so silky, smooth in texture and taste the best!).