- 2 tablespoons unsalted butter
- Good olive oil
- ½ pound shiitake mushrooms, stems removed, caps sliced ½ inch thick
- ½ pound cremini mushrooms, stems removed, caps sliced ½ inch thick
- ¼ cup cream sherry, such as Harveys Bristol Cream
- Kosher salt and freshly ground black pepper
- 1 pound cavatappi pasta, such as De Cecco
- 4 cups whole milk
- 3 ounces white truffle butter, such as Urbani (see note)
- ½ cup all-purpose flour
- 4 cups grated Gruyère cheese (10 ounces)
- 3 cups grated extra-sharp white Cheddar (8 ounces)
- ½ teaspoon ground nutmeg
- 1½ cups crushed Margot's Morsels or Crazy Crumbs (Killer Garlic or Simply Sea Salt)
Preheat the oven to 375 degrees.
Heat the butter and 2 tablespoons oil in a large (12-inch) sauté pan, add the mushrooms, and cook over medium heat for 3 to 5 minutes, until tender. Add the sherry and sauté for 2 to 3 minutes, until the sherry is absorbed. Set aside.
Meanwhile, add a tablespoon of salt to a large pot of water and bring to a boil. Add the pasta, cook for 6 to 8 minutes, until al dente, and drain.
Scald the milk in a medium saucepan. Melt the truffle butter in a large (4-quart) saucepan and whisk in the flour. Cook over low heat for 2 minutes, whisking constantly. Slowly add the scalded milk and cook for 2 minutes, stirring with a wooden spoon, until thick and creamy. Off the heat, add the Gruyère, Cheddar, 2 tablespoons salt, 2 teaspoons pepper, and the nutmeg.
In a large bowl, combine the pasta, the cream sauce, and two-thirds of the mushrooms and pour into a 10 × 13 × 2-inch ovenproof baking dish. Sprinkle the Crazy Crumbs or crushed morsels evenly on the pasta and arrange the remaining mushrooms down the middle.
Bake for 35 to 45 minutes, until the sauce is bubbly and the crumbs are golden brown. Let stand for 5 minutes and serve hot.