Peel and chop the potatoes into 2cm squares. Try to ensure they are cut into equally sized pieces to ensure even cooking.
Place the potatoes into the Thermomix bowl.
Add the milk and salt. Cook for 20 minutes / 100 degrees / speed 1.
At the end of the cooking time, check the potatoes. They should be very tender and falling apart.
Insert the butterfly.
Add the butter. Mash for 5 seconds / speed 3.
Check the potatoes. Repeat for 5 seconds / speed 3, if necessary.
Serve with some extra butter on top and a sprinkle of chopped parsley or chives.
