Just when you thought there was nothing new to do with potatoes…I discovered this in the New York Times. It’s kind of labor-intensive, and it takes a long while to cook, so plan ahead. But it tastes great!
3 oz. finely grated Gruyere cheese
2 oz. finely grated Parmesan cheese
2 cups heavy cream
2 cloves garlic, minced or pressed
1 Tblsp fresh thyme leaves
Salt and black pepper to taste
4 pounds of russet potatoes (the floury kind, like baking potatoes, not the waxy kind. Try to find evenly shaped ones, not irregular lumpy ones.)
2 Tblsp soft butter
Preheat the oven to 400 degrees (you might want to put a cookie sheet on a lower shelf, in case this dish bubbles over). Grease a 2-quart casserole dish with the butter.
Combine the grated cheeses in a bowl, then put 1/3 of the mixture in another bowl and set aside.
Peel and slice the potatoes, about 1/8” thick. I used my food processor with the thicker slicing blade, but of course you can do it by hand if you want. Or use a mandoline (a manual kind of slicer)—but those scare me because I’m always sure I’m going to slice my finger.
To the first bowl, add the cream, garlic and thyme to the cheeses, then the salt and pepper. Mix, then add the potato slices.
Now comes the fun part. Gently toss the slices in the cheese/cream until every slice is well coated. Make sure none of them stick together. You really have to use your hands for this, because a spoon might break the slices, and whole slices are important for the next part.
Putting it together:
Pick up a bunch of potatoes and arrange them in a neat stack. Stick them vertically in the casserole dish, so the edges stick up. Go around the dish, starting with the outside ring, packing the slices tightly (If you run out, you may have to peel another potato, slice it, and cover it with cream, then fill in the casserole.)
This takes three steps.
--Cover the dish with foil and place in the oven. Bake for 30 minutes in the preheated oven.
--Remove the foil from the dish. Return to the oven and bake for another 30 minutes, until the top starts browning.
--Take it out of the oven (carefully! It’s hot!) and sprinkle the reserved cheese over the top. Return to the oven and bake for another thirty minutes (yes, you’re now up to 90 minutes cooking time), until the top is deep golden brown and crisp.