Peel potatoes and cut them into cubes, about ½ to 1 inch each.
Place cubes in a slow cooker and cover with water
Cook on high for about 4 hours, or low for about 7 hours.
It’s OK to leave fully cooked potatoes on “warm” until shortly before serving, up to 2 hours.
Check that the potatoes are fully cooked, then drain the water.
Add butter, milk, salt and pepper.
Turn the slow cooker off. Mash with a potato masher right in the slow cooker. Add more salt and pepper if needed.