Spray the Instant Pot liner with nonstick cooking spray.
Add water, noodles, and salt. Stir. Place the sealing ring into place in the lid. Secure the cover.
Pressure cook the noodles on high for 3 minutes.
Allow the pressure cooker to do a natural release for 1 minute. After one minute do quick release of the pressure. Do not drain.
Dice up the butter into small pieces. Add butter to the cooked noodles. Carefully stir the butter and noodles until melted.
Add shredded cheese in small batches, along with two tablespoons of milk at a time. As it sits, it will thicken up. Add more milk as needed.
Notes
Note 1: I have also tested gluten free noodles (Barilla Brand) and it works great too!Storage Notes: Keep leftovers in an airtight container in the refrigerator. Enjoy within 3-4 days. Reheat with a splash of milk and a handful of cheese. Do not freeze.