A classic creamy mushroom-potato gratin recipe, with cremini mushrooms and plenty of cheese. Make sure to peel and slice the potatoes at the last minute, and don’t soak them in water or you will remove all the starch, which helps thicken the gratin.
- Yield: 6 to 8 servings
- Difficulty: Easy
- Total: 45 mins
- Active: 20 mins
- 3 tablespoons unsalted butter
- 1 small yellow onion, finely chopped
- 1 teaspoon kosher salt
- 1 pound cremini mushrooms, sliced
- 2 teaspoons minced fresh thyme
- 1⁄4 teaspoon freshly ground black pepper
- 2.5 pounds russet potatoes, peeled and sliced 1/8-inch thick
- 1 cup low-sodium chicken broth
- 1 cup heavy cream
- 2 bay leaves
- 2 packed cups shredded Gruyère, Fontina, or white cheddar cheese
- Preheat the oven to 400°F. In a stockpot or large saucepan over medium-high heat, melt the butter. Add the onion and salt and cook, stirring occasionally, until softened, about 4 minutes. Add the mushrooms, thyme, and pepper and cook until the mushrooms are tender, about 5 minutes. Scrape into a bowl.
- Put the potatoes, broth, cream, and bay leaves into the stockpot and bring to a simmer. Cover, reduce the heat to medium-low, and simmer until the potatoes are almost tender, about 10 minutes. Remove the bay leaves.
- Transfer the mixture to a 1 1/2-qt baking dish. Sprinkle with the cheese. Bake until bubbling and golden brown, about 20 minutes. Let cool for about 5–10 minutes before serving.