Earthenware dishes with a large surface area, that are shallow, low sided, and glazed on the inside, are perfect for slow-cooking in the oven and the formation of the golden crust of a gratin.
Cooks' Note
Other sliced vegetables can be combined with the potatoes: turnips, celery root, leeks, winter squash, mushrooms, as well as wilted leafy greens between the layers. Apply the same method to other vegetable gratins without potatoes.
