This Classic Italian Pasta Dish Is the Adult Way to Eat Ham and Cheese

Name: This Classic Italian Pasta Dish Is the Adult Way to Eat Ham and Cheese
Ingredients: 3 tablespoons unsalted butter(1 1/2 ounces; 40g); 3 tablespoons (24g) all-purpose flour; 2 cups (480ml) whole milk; Kosher salt and freshly ground black pepper; Pinch freshly grated nutmeg (optional); 1 pound (450g) store-bought or homemade fresh lasagna noodles (if homemade, follow the recipe and instructions here through step 10), cut into 6- by 12-inch rectangles; Vegetable oil, for greasing pan and pasta; 8 ounces (227g) fontina, rinds trimmed and cut into 1/4-inch pieces; 1 cup finely grated Parmigiano-Reggiano (4 ounces; 112g), divided, plus more for garnish; 8 ounces (227g) prosciutto cotto, torn into into 2-inch pieces