Gratin dauphinois — Dauphiné, France

Gratin dauphinois is a potato dish built on milk and cream alone, with no cheese, its layers held together only by the starch the potatoes release during a long, slow bake. That absence of cheese is often the first thing pointed out about it, since a similar-looking gratin made with Gruyère is generally classed as a separate, Savoyard dish. It is first recorded in writing in 1788, at a dinner given for the municipal officers of the town of Gap by a local nobleman, and it is reported across the wider Dauphiné province — Grenoble, Vienne and Gap among its towns — rather than tied to one place in particular. Firm-fleshed potatoes are peeled and sliced thinly, left unwashed so their starch is not rinsed away, then layered raw in a garlic-rubbed, buttered dish with salt, pepper and a little nutmeg between the layers. Milk and cream, mixed with more garlic, are poured over just to the level of the potatoes, and the dish is baked slowly at a low temperature so the starch has time to bind the liquid before a brief hotter spell browns the surface. What distinguishes this preparation among the region's potato gratins is exactly this reliance on time and starch rather than added cheese or eggs to thicken the cream: the low, long oven does the binding, and the potatoes are meant to hold their shape in slices rather than collapse into a mash.