It likely has something to do with the fact that I recently gave birth and am just now emerging from the newborn craziness, but it feels like this year is flying by at lightning speed. April is always a busy time for our family – there is Easter, of course, but three out of four of us also celebrate our birthdays this month. Now that the calendar has turned, I am suddenly feeling rather unprepared for all the merry-making that is to come. I suppose I better kick things into high gear and turn my lofty dreams into specific plans, lest I find myself disappointed in the end due to my lack of planning.
If you find yourself in a similar position, less than a week from Easter and not altogether sure of what you’ll be making for the holiday dinner, may I submit to you this Thyme-Infused Potato Gratin. Rich and decadent, this side dish is fit for a celebration. There is an atrocious amount of heavy cream involved, but once you taste the finished product, I don’t think you’ll mind one bit. It’s not something I’d eat every day, or even every week, but for a special occasion, it’s worth the splurge.
In this easy-to-prepare gratin, several layers of flavor come together to provide a taste experience that is satisfying and complex. The fresh thyme brings subtle earthiness to the buttery Yukon gold potatoes; the parmesan provides tanginess; and the sautéed onions and garlic contribute an unconventional element to this traditional casserole.
- 3 tablespoons butter, divided
- 2 1/2 cups heavy cream
- 7-8 sprigs fresh thyme
- 2 bay leaves
- 1 cup finely diced yellow onion
- 3 cloves fresh garlic, finely minced
- 2 1/2 pounds Yukon gold potatoes (scrubbed clean, peel-on)
- 1 1/2 cups finely grated parmesan cheese
- 1/2 teaspoon kosher salt
- 1/8 teaspoon freshly ground black pepper
- Preheat the oven to 400 degrees. Use clean fingers or a paper towel coat the inside of a 2 ½ quart casserole dish with 1 ½ tablespoons of butter.
- In a medium saucepan over medium heat, warm the heavy cream, thyme, and bay leaves until the mixture just simmers (don’t allow it to boil). Remove the pan from the heat and set aside, allowing the flavors of the thyme and the bay to infuse the cream as it sits.
- As the cream is heating up, melt the remaining 1 ½ tablespoons of butter in a sauté pan over medium high heat. Once the butter is melted, add the diced onion and 1/8 teaspoon kosher salt, and allow the mixture to cook for 3 minutes, stirring occasionally. Stir in the minced garlic and sauté 3-4 minutes more. Remove the pan from the heat and set aside.
- Use the thinnest option on a mandoline slicer to cut the potatoes into 1/16 inch slices. If you do not have a mandoline, use a sharp knife to slice the potatoes as evenly and thinly as possible (it will be difficult to get the slices any thinner than 1/8 inch if cutting by hand, but that’s okay!). Two and a half pounds of sliced potatoes should yield about 8 cups.
- In a large mixing bowl, add the potato slices, sautéed onions and garlic, grated parmesan, ½ teaspoon kosher salt, and pepper. Pour the infused cream through a fine mesh strainer into the bowl, discarding the thyme sprigs and bay leaves. Use a wooden spoon to gently toss together the ingredients until combined.
- Arrange the potato slices in even layers in the prepared casserole dish. Pour any remaining cream mixture over the potatoes and finish with a sprinkle of fresh thyme leaves (about ½ teaspoon).
- Cover with foil and bake until the potatoes are tender, about 1 hour and 20 minutes. Then, remove the foil and cook for 10 minutes more until the top of the potatoes are golden. Let the gratin rest for 15 to 20 minutes before serving to allow the cream sauce to set.