Peel and cut the potatoes into 1-2 inch cubes. Place in a medium pot and cover with cold water; add 1 tablespoon of salt. Place over a low heat and let simmer until fork tender. Drain potatoes using a colander. Put potatoes into a bowl. Using an hand held electric beater mix potatoes on medium high speed until most of the lumps have disappeared; about 1 minute. Add butter; mix until blended. On low speed add hot milk in a slow and steady stream; then add pepper, nutmeg, and salt to taste. Mix to combine.