I use the Oxo Good Grips Potato Masher to mash directly in the Instant Pot. (It’s also fantastic for mashing avocados for guacamole or eggs for egg salad. This masher is one of my top favorite kitchen tools.)
Low FODMAP Diet Note: Make sure that your milk and butter are lactose-free. As always, check the Monash FODMAP app for recommended serving/portion size.