Cheesy Au Gratin Potatoes
*Note: the key to this dish is the evenly and very thinly sliced potatoes. It will be nearly impossible to accomplish this feat by hand, since the potatoes need to be sliced 1/8-inch thick. I don't have a mandoline, which would work perfectly, however, a slicing disk on a food processor/shredder works great and in a pinch, I've used the slicing side of my box grater.
1 1/4 cups shredded sharp cheddar cheese
1 1/4 cups shredded Monterey jack cheese
1/2 cup grated Parmesan cheese
2 teaspoons cornstarch
3 pounds russet potatoes, peeled and sliced 1/8-inch thick
Salt and pepper
3/4 cup heavy cream
1/2 cup low-sodium chicken broth
Preheat the oven to 350 degrees and adjust an oven rack to the middle position. In a large bowl, toss the cheeses and cornstarch together until evenly coated.
In a large gratin dish (about a 2- to 3-quart dish), shingle half of the potatoes. Sprinkle the potatoes evenly with 1 1/2 cups of the cheese mixture, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Top with the remaining potatoes, shingling them neatly and evenly. Sprinkle another 1/2 teaspoon salt and 1/4 teaspoon pepper evenly over the top.
Combine the cream and the broth in a large measuring cup and pour the mixture over the potatoes. Top with the remaining cheese mixture and bake until golden brown and a fork inserted into the center slides in easily with little resistance, 75 to 85 minutes. Let the potatoes cool for 10 minutes. Serve.