Potato Gratin With Porcini Mushrooms and Mascarpone Cheese

Total Time
1hr 45mins
Prep 30 mins
Cook 1 hr 15 mins

Submitted by Ingrid Quillen for Mascarpone Madness.

Ingredients Nutrition


  1. Place porcini mushrooms in a medium bowl and cover with boiling water. Place a small bowl atop the mushrooms so that they stay submerged in the hot water. Soak for 20 minutes, then drain and coarsely chop the mushrooms.
  2. Place butter and oil in a medium skillet over medium heat. When the butter has melted add the mushrooms and saute just until they begin to brown, about 3 minutes. Sprinkle with salt and pepper and remove from heat. NOTE: this step can be done the day ahead. Refrigerate the browned mushrooms until ready to use.
  3. Whisk 1/4 cup parmesan, the mascarpone, whipping cream, garlic and nutmeg in a small bowl. Add salt and pepper to taste. NOTE: this step can be done the day ahead - simply cover the bowl and chill until ready to use.
  4. Preheat the oven to 325°F Butter a wide shallow 2-quart baking dish. Arrange 1/4 of the potato slices in the bottom of the dish. Sprinkle lightly with salt and pepper. Scatter 1/4 of the mushroom mixture over all. Follow with another layer of 1/4 of the potatoes, and another layer of 1/4 of the mushrooms. Spread half of the cheese mixture over all, shaking the dish if necessary to allow the layers to settle.
  5. Cover the cheese layer with a layer of potatoes, a layer of mushrooms, another layer of potatoes and the last of the mushrooms. Finally spread all of the remaining cheese mixture over the top. Sprinkle the 2 tablespoons of parmesan over all.
  6. Place the gratin dish on a rimmed baking sheet. Bake until the top is brown and the sauce is bubbling at the edges, about 1 hour and 15 minutes. Let rest 15 minutes before serving. NOTE: this dish can be made 2 hours ahead of time. Let stand at room temperature. Tent loosely with foil and rewarm at 300 F for 20 minutes.