How to Make It
Combine macaroni and water in a 6-quart programmable electric pressure cooker (such as an Instant Pot). Cover Instant Pot, and fasten lid. Lock and seal steam valve. Set to HIGH pressure for 4 minutes. (The pot will take about 15 minutes to come up to pressure before the cooking program begins.)
When cooking program ends, carefully release pressure quickly by turning Pressure Release to VENT. (Steam is fully released when pressure valve drops.) Uncover and turn off Instant Pot. Drain pasta and set aside.
Set Instant Pot to SAUTE. Add milk and bring to a low simmer, about 2 minutes. Whisk in flour until smooth and mixture begins to thicken, 1 to 2 minutes. Whisk in cream cheese, hot sauce, salt, mustard and pepper until smooth. Gradually whisk in cheese until melted, about 1 minute. Turn cooker off. Add pasta and stir to coat. Serve immediately.