Stir macaroni, butter, mustard, hot sauce, salt, and water in the Instant Pot. Lock the lid and cook on high pressure for 4 minutes. Quick release the pressure and remove lid.
Turn on Saute Setting. Stir in the evaporated milk. Add cheese one handful at a time, stirring constantly allowing cheese to melt between each handful.
Remove from heat. Set for 2 minutes for the milk and cheese to completely absorb the pasta and serve!
Video
Notes
Note: You must let it rest before serving or it will be soupy.