These mashed potatoes have no milk or cream; instead, I use sour cream and cream cheese, plus a little bit of Dijon mustard and a lot of roasted garlic. They are tangy and creamy and on the stiffer/drier side. As in, they would be able to hold their shape if they were served with an ice-cream scoop in a school cafeteria. In my book, that simply means that they're just right on the night that you make them (want to sculpt a mashed potato mountain with a gravy lake? go for it), and they're the perfect texture for making potato cakes a few days later. —pantryhero
2 if you want lots of leftovers for potato cakes; 4-6 if you don't
whole head of garlic
Yukon Gold potatoes, peeled and cut into 1" chunks
Preheat the oven to 4ooº. Slice the top 1/2" or so off of the head of garlic. Place it on a piece of aluminum foil, drizzle with a little olive oil, and seal the foil tightly. Roast for about 45 minutes, or until the garlic is soft. (Now is a good time to take the cream cheese, sour cream, and butter out of the fridge.) Cool slightly.
Bring the potato chunks to a boil in a pot of salted water (salt it like you would pasta water), then turn the heat down to maintain a low boil and cook until fork-tender, about 10 minutes. Drain well. I usually shake them around in the warm pot again after I drain them, just to make sure they're nice and dry.
Mash the cooked potato chunks with next 5 ingredients (cream cheese through kosher salt) and the cooled roasted garlic—just squeeze the head of garlic, and the soft roasted cloves will come out of their skins where you chopped the top off; no need to peel individual cloves. Add more salt if desired and freshly ground pepper to taste.