Name: Potato Gratin With Gruyère and Thyme
Cook time: P0Y0M0DT0H40M0.000S
Total time: P0Y0M0DT2H20M0.000S
Yield: 8 servings
Ingredients: 1 1/2 cups heavy cream; 1 cup low-sodium chicken broth; 2 cloves garlic, minced; 2 teaspoons fresh thyme; Kosher salt and freshly ground pepper; 3 1/2 pounds Yukon Gold potatoes, peeled and sliced into 1/8-inch-thick rounds on a mandoline; Unsalted butter, for the baking dish; 3/4 cup shredded Gruyère cheese; 1/4 cup grated Parmesan cheese

Directions

Combine the heavy cream, chicken broth, garlic, 1 teaspoon thyme, 2 1/4 teaspoons salt and a few grinds of pepper in a large skillet; add the potatoes. Bring to a boil, then reduce the heat to medium-low to maintain a gentle simmer. Cook, gently pressing down on the potatoes to submerge and flipping the top slices once or twice, until just tender when pierced with a knife, 6 to 10 minutes. Let cool 10 minutes.
Butter a 3-quart baking dish. Add the potato-cream mixture, being sure to scrape out all the liquid. Let cool to room temperature, about 20 minutes, then top with the Gruyère, Parmesan, the remaining 1 teaspoon thyme and a few grinds of pepper. At this point, you can cover the potatoes with foil and refrigerate up to 3 days; remove from the refrigerator about 30 minutes before baking.
Preheat the oven to 375 degrees F. Bake the potatoes, covered, until the edges start to bubble, about 30 minutes, then remove the foil and continue baking until evenly golden brown on top, 30 to 35 more minutes. Let sit 15 minutes before serving.