Gratin of Potatoes in the Style of the Auvergne

In the original édition of this book, I presented a recipe for a rustic dish called le gatis—a mixture of Cantal and Roquefort cheeses served melting hot in a crust of brioche. (You’ll find the recipe on my website, paulawolfert.com.) Here’s a recipe for a luscious gratin that uses the same combination of cheeses along with slices of potatoes.

You can substitute a nice English Cheddar or a Monterey Jack for the hard-to-find Cantal, but please use a good blue-veined cheese—rea