Pour chicken broth and 1 pound of Cavatappi noodles into the Instant Pot. Top with butter, salt and pepper, and stir.
Seal the Instant Pot lid closed and press manual. Set the timer to 5 minutes and make sure the seal is closed.
Manually vent after the pasta cooks and the timer goes off.
Once it is safe to open the lid, pour the evaporated milk and cheese over the pasta and stir until melted.
Remember that the 5 minute cook time isn't the total cook time. It will take some time for your Instant Pot to come to pressure before the actual cook time begins. Depending on how much liquid is in the pressure cooker, it can take 5 to 30 minutes.