Potato and Wild Mushroom GratinPhoto Credit : Jamie Salomon
Damian Sansonetti, chef-owner of Piccolo restaurant in Portland, Maine, created this potato mushroom gratin in the French style, with mushrooms and potatoes layered and baked in a creamy cheese sauce until browned and bubbling.
3 tablespoons salted butter, plus more for the baking dish
1 small onion, diced
3 garlic cloves, minced
1 teaspoon chopped fresh oregano
1/8 – 1/4 teaspoon ground cayenne pepper
1 cup heavy cream
1 1/2 cups whole milk
Salt and pepper, to taste
3 tablespoons olive oil
1 pound mixed wild mushrooms (preferably hen of the woods and oyster), cleaned and diced
2 pounds russet potatoes, peeled and sliced into 1/8-inch-thick rounds
2 tablespoons chopped fresh parsley
1 cup grated pecorino or Parmesan
Preheat the oven to 350° and set a rack to the middle position. Grease a 2- or 3-quart baking dish with butter and set aside.
In a 3- or 4-quart pot over medium-high heat, melt butter until lightly browned. Add onion, garlic, oregano, and cayenne, and cook, stirring, until the onion is translucent, about 6 minutes. Stir in the cream, then the milk. Bring to a boil, stirring, then immediately remove from heat. Purée with an immersion blender or in a standing blender until smooth. Add salt and pepper to taste, and set aside.
In a large skillet over high heat, sauté the mushrooms in the olive oil until nicely browned, 5 to 7 minutes. Place sliced potatoes in a large bowl and add the cream mixture, mushrooms, and parsley. Using your hands or a wooden spoon, blend mixture, making sure to separate and coat all the potato slices.
Pour mixture into the prepared baking dish and gently smooth the top. Sprinkle with cheese and bake until potatoes are fork-tender and the top is lightly browned, about 1 hour. Serve warm.