Add noodles, butter, water, ground mustard, red pepper flakes, salt, and pepper to the Instant Pot. Close lid and cook and manual, high pressure for 4 minutes.
Open valve for quick release. Remove lid.
Add the cheeses and evaporated milk. Stir to combine and until cheeses are melted.
Add the bacon and jalapenos and stir to combine.
Garnish with additional bacon and jalapenos if desired.
Serve immediately.
Store any remaining mac and cheese in an airtight container in the refrigerator for up to 3 days.
