Croque Monsieur Mac and Cheese

Name: Croque Monsieur Mac and Cheese
Ingredients: Nonstick cooking spray or unsalted butter, at room temperature, for the casserole dish; Kosher salt and freshly ground black pepper; 8.8 ounces (250 grams) dry rigatoni; 2 tablespoons unsalted butter; 1 garlic clove, minced; 3 tablespoons all-purpose flour; 2 cups (500 milliliters) plus 2 tablespoons (60 milliliters) milk; 3/4 teaspoon herbes de Provence; Pinch freshly grated nutmeg; 2 teaspoons Dijon mustard; 1/2 cup (55 grams) grated pecorino; 2 1/2 cups (285 grams) grated Gruyère; 7 ounces (200 grams) thinly sliced deli ham, roughly chopped; 1 large egg; 2 slices bread, roughly torn into small pieces