Truffle Mac and Cheese

Name: Truffle Mac and Cheese
Ingredients: 2 tablespoons unsalted butter; Good olive oil; 1/2 pound shiitake mushrooms, stems removed and caps sliced 1/2-inch; 1/2 pound cremini mushrooms, stems removed and caps sliced 1/2-inch; 3 tablespoons cream sherry; Kosher salt; 1 pound pasta, such as cavatappi; 3 ounces white truffle butter (recommended: D'Artagnan); 1/2 cup all-purpose flour; 1 quart whole milk, scalded; 12 ounces Gruyere cheese, grated (4 cups); 8 ounces extra-sharp Cheddar, grated (2 1/2 to 3 cups); 1 teaspoon freshly ground black pepper; 1/2 teaspoon ground nutmeg; 2 garlic cloves, chopped; 3 tablespoons freshly chopped parsley leaves; 1 1/2 cups fresh white bread crumbs