Gratin Dauphinois

Cooks fight about what makes the authentic version of this dish – unrinsed floury potatoes for the starch to hold the dish together or rinsed waxy potatoes for a lighter texture; milk, cream, crème fraîche, or a combination for the liquid. There are other debates about whether to use egg yolk or a little flour to thicken the mix; whether cheese is essential or nutmeg heresy. Most agree on the use of butter and garlic – Edouard de Pomiane, writing in the 1930s, has 4 cloves of garlic to