First, of all, I’m the worst at giving proportions in a mashed potato recipe. I’ve never measured anything when I make them, ever.
Scrub baking potatoes, cut into large even chunks. Or peel, according to your whim. I’ll just tell you that the nutrients are mostly in the peel & you can have that on your conscience. Put into water and bring to a boil. Boil until cooked but not crumbling. Drain well in a colander AND SAVE THE COOKING WATER – let potatoes sit until they are getting that white starchy look a bit. This is very important & solves most cases of poor mashed potatoes.
Turn potatoes back into the pan. Add:
Butter (2 T. for a 5 qt. pot of potatoes.)
Salt (you need more than you think)
Pepper (you need more than you think)
Milk 1/2 c. to start (too much gives them an unpleasant sweet-milky flavor)
Mash or put through a ricer. Once you’ve started to get somewhere, add potato water a little at a time as you mash to get to the right texture. If you’ve riced your potatoes, mash in any later additions of seasoning – stirring mashed potatoes makes them gluey.