On that cool morning, as Anderer walked me through the recipe in the basement kitchen, where his cooks prepped the day’s service to a soundtrack of Spanish Christian rock music, I learned a few key lessons: First, use Yukon Golds, which are more consistently delicious than some old russets on the shelves. When peeling them, don’t worry about the odd bit of skin; you won’t notice them in the final product, Anderer said, jokingly calling his technique a “rustic peel à la Anton’s.” Second, really take the time to mash, mill or rice the potatoes, cutting in cold butter as you do (it will melt). I find that a fork, with a good measure of diligence, gets you to the finest, most even mash. Once you add the liquid, overmixing can lead to glueyness, so do as Anderer does and gently fold the milk and olive oil into the potatoes as if you’re dressing a salad, until, he said, “every bit of potato is moistened and seasoned.”