Add potatoes and salt to a large pot, cover with water by about 2 inches. Bring to a boil and cook until tender when pierced with a knife, but not falling apart (check several) about 20 to 25 minutes.

Drain the potatoes well, return to hot pot, and let them sit for a bit to dry. Gently turn with a spatula if needed. Turn burner back to low heat if needed. Once the potatoes are dry and most of the steam has dissipated, mash, making sure to get the potatoes from the bottom edges of the pot, using a spatula if needed. When broken down, add the butter and mix until just incorporated. No need to be perfect.  Don’t over do it. Too much mixing can make the potatoes water or gluey. Take off heat and add the cream cheese, sour cream, and milk, then salt and pepper to taste. Mix in gently to combine, preferably by hand.

Don’t mess with these after they’re all mashed and stirred together; they can get overworked and/or watery. Trust the process. Better to have a lump here or there than overworked/watery potatoes.

If planning to reheat by baking, place in casserole dish and refrigerate. Cover when cold. Reheat at 350 degrees, covered, for about an hour topping with additional butter before baking. Top with chives before serving if desired.

If reheating in the slow cooker, refrigerate potatoes in a container (not the slow cooker liner) and cover when cold. To reheat, add the potatoes to the slow cooker, cover and cook on low until potatoes are hot and warmed through, one to two hours, giving a stir about halfway through. They can be held for about an hour longer or so and still be at their absolute optimum. If they have to be held longer, that’s ok, but not absolutely ideal. Before serving, top with butter and chives. If recipe has been doubled, it’s best to heat the potatoes carefully on the stovetop before placing in the slow cooker.