(adapted from CasaLana)
Makes 12 servings
4 ounces white cheddar cheese, grated
4 ounces blue cheese, crumbled
1 ounce Parmesan cheese, grated
3 pounds Yukon Gold potatoes, washed
2 tablespoons unsalted butter
1 yellow onion, diced small
3 - 4 cloves garlic, minced
1 - 1½ teaspoons thyme
1 cup heavy cream
Kosher salt
Freshly ground black pepper
½ cup bread crumbs
Preheat the oven to 350°F. Using butter or pan spray, coat the bottom and sides of a 9-by-13-inch baking dish.
In a small bowl, combine the cheddar, blue, and Parmesan cheeses, and set aside.
Using a mandolin, V slicer, or knife, slice the potatoes thin (about ¼ inch thick) and place in cold water to keep them from discoloring.
In a medium-size sauté pan, heat the butter over medium heat until melted, then add the onions and cool until soft and translucent, about 5 to 7 minutes. Stir in the garlic and thyme and cook for another minute. Remove the pan from the heat and set aside.
Drain the potatoes and pat dry. Place a single layer of potatoes slices in the bottom of the greased baking dish, overlapping slightly. Sprinkle one-third of the onion mixture on top of the potatoes; then, sprinkle one-fourth of the cheese mixture on top of the onions. Repeat layering the potatoes slices, onion mixture, and cheese mixture two more times. Top with one more layer of potato slices and sprinkle with remaining cheese mixture, then pour the heavy cream evenly over the potatoes. Sprinkle the bread crumbs evenly over the top.
Bake the potatoes for approximately 45 minutes or until the potatoes are tender when pierced with the tip of a sharp knife. If the bread-crumb topping is getting too brown too quickly, cover the pan loosely with aluminum foil.
Remove the potatoes from the oven and let sit, covered, for 10 minutes before serving.
