Combine uncooked pasta, water, and butter in the basin of your Instant Pot. Make sure the water comes to the top of your noodles, so that the topmost parts are just under the water.
Close the lid, seal it, and turn your steam release valve button to the “sealed” position.
Press “Pressure Cook”, set to high pressure, and select 2 minutes. It will take around 6-7 minutes to reach pressure, then the 2 minutes will begin.
Once the timer goes off, press “Cancel”, and turn the steam release valve to do a quick release until the steam starts to run slow.
Open the Instant Pot and stir to break up the noodles.
Stir in the cheddar, evaporated milk, salt, pepper and dry mustard until thoroughly mixed.
Place the lid back on the instant pot and press the “Keep Warm” button. Let it sit for 5-10 minutes, then turn the pot off and open the lid.
Stir melted cheese thoroughly until creamy and coated. Mixture will thicken as it cools.
Use any flavor cheese you love with this recipe. I am using white cheddar here but you can use any mild cheese that melts well.
Sometimes when you do a "quick release" after cooking pasta, the pasta water will spit out. If this happens, close the valve and slowly let the pressure release. Or you can put a kitchen towel over it to help.
You can really use any pasta shape. I usually use elbow macaroni or cavatappi (which is the corkscrew looking pasta.)
For extra cheesiness, try adding additional shredded cheese on top of the fully cooked macaroni and cheese mixture. Place the lid back on and allow the cheese to melt before serving.