Cut the potatoes into circles 1 inch thick, cover with salted water in a saucepan.
Bring to a boil and simmer until tender.
Drain, return to saucepan and add butter.
Crush the pulp with a masher using an up and down motion. Don't over mix.
Add the heated milk and mix with a gentle up and down motion.
The potatoes should be fluffy. It is better to have them a little thin at first as they "set up" as they sit.
Salt and pepper to taste.
I personally don't like the flavor of white pepper and don't use it. Some don't like to see black specks in their food. It is up to you. A ricer is an option instead of a masher. It is hard to get the right texture by using an electric beater. It tends to over whip and the potatoes can get gummy.