Food & Cooking Recipes Main Dish Recipes Casserole Recipes Lemon-and-Thyme Potato Gratin 3.5 (120) Add your rating & review By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on January 28, 2021 Print Rate It Share Share Tweet Pin Email Photo: Dana Gallagher Servings: 4 Lemon zest gives this potato gratin recipe real lemon flavor without making the milk curdle. Ingredients 2 tablespoons unsalted butter, plus more melted for pan 2 pounds Yukon gold potatoes, peeled and sliced very thinly 2 teaspoons chopped fresh thyme leaves ⅛ teaspoon freshly grated nutmeg Zest of 1 lemon, finely chopped (2 teaspoons) Salt and freshly ground black pepper 1 cup milk Directions Heat oven to 400 degrees with rack in center. Place a baking sheet on rack below to catch any drips from gratin. Brush a 10-by-5 1/2-inch gratin dish with melted butter. Cover bottom of gratin dish with one-third of potato slices in an even layer. Sprinkle potatoes with one-third each of thyme, nutmeg, and lemon zest; season with salt and pepper. Dot with butter. Add a second layer, and season. Top with a third layer of neatly arranged potato slices. Pour milk over potatoes. Sprinkle with remaining third thyme, nutmeg, and lemon zest, and dot with butter. Season to taste with salt and pepper. Cover with foil. Bake for 40 minutes. Remove foil, and continue to bake 10 to 20 minutes, until top is golden brown and potatoes are tender when pierced with the tip of a knife. Serve gratin hot, spooned out into individual servings. Rate it Print