This is not the potato dish I made for my big Thanksgiving meal last year. Last year, I made a potato and wild mushroom gratin, which followed my goal of including more vegetables in the meal. This gratin doesn’t fit that theme.
Here’s the thing though: I cannot remember anything about that dish. I don’t remember it being bad, at least, but I don’t remember how good it was. Maybe there were too many mushrooms? I don’t know.
I only made this Yukon gold and sweet potato gratin last week, but even if it had been last year, I know I would remember it. Potatoes baked in herby cream sauce and topped with nutty cheese are usually a hit, but adding sweet potatoes to the mixture makes it even better. I can’t guarantee the same thing for adding wild mushrooms to potato gratin.
One year ago: Green Chile Mayonnaise
Two years ago: Wheat Berries with Caramelized Onions, Feta, and Lentils
Three years ago: Bacon-Wrapped Pork Tenderloin Medallions
1½ pounds medium Yukon Gold potatoes, peeled, sliced ⅛-inch thick
1½ pounds medium red-skinned sweet potatoes (yams), peeled, sliced ⅛-inch thick
1 cup heavy cream
1 cup whole milk
2 tablespoons butter
2 garlic cloves, minced
2 tablespoons minced fresh thyme
1½ teaspoons salt
¾ teaspoon black pepper
1¼ cups (5 ounces) coarsely grated Gruyére cheese
2. Heat the oven to 400 degrees. In a small saucepan, combine the cream, milk, butter, and garlic; bring to simmer. Remove from the heat.
2. Butter a 13x9x2-inch glass baking dish. Evenly spread half of the potatoes on the bottom of the dish. Top with half of the thyme, salt, pepper, and cheese. Repeat the layering with the remaining potatoes, salt, pepper, and cheese. Pour the cream mixture over the gratin, pressing lightly to submerge the potato mixture as much as possible. (Can be made 6 hours ahead. Cover with plastic wrap and chill. Remove plastic wrap before baking.)
3. Cover the gratin tightly with foil. Bake 30 minutes. Uncover and continue baking until the top of the gratin is golden and most of the liquid is absorbed, about 25 minutes longer. Let stand 10 minutes before serving.