Place the potatoes in a pan and cover with salted water.
Bring to a boil and cook until tender (approx. 20 minutes).
Drain immediately.
Pass through a ricer or use a potato masher to make a smooth puree.
Mix in the butter and milk, then season to taste with the salt, pepper and nutmeg.
Serve as a side dish or incorporate into other dishes as required.
Notes
Depending on the use for the potatoes, the quantities of butter and milk can be adjusted. A super rich version in the style of some exclusive restaurants can be made by greatly increasing the amount of butter incorporated, to almost equal the volume of potato. (See Joel Robuchon).