Serves 10 Difficulty
Unsalted butter for greasing baking dish 3 Tablespoons olive oil 2-1/2 lbs Yukon potatoes, peeled and cut into 1/8” sliced 1-1/2 teaspoons kosher salt ¾ teaspoon fresh ground pepper 1-1/4 cup cream 1 cup Parmesan cheese 2 Tablespoons chopped thyme 6 garlic cloves, thinly sliced 12 ounces cremini mushrooms, sliced
Preheat oven to 375 degrees F. Grease a 13x9x2 inch baking dish with unsalted butter. Place 1/3 of potatoes layered in dish. Sprinkle with ½ teaspoon salt and ¼ teaspoon pepper. Add 1/3 cup cream and ¼ cup parmesan cheese. Repeat with two more layers. Bake uncovered for 45 minutes; remove from oven. Sprinkle thyme and garlic slices on top of gratin. Add mushrooms to a medium bowl and toss with oil; season with salt and pepper. Sprinkle mushrooms evenly over top of gratin and drizzle top with ¼ cup cream, then remaining cheese. Bake for an additional 20 minutes.