Surprise Corn Casserole | Lazy Cooking

Ingredients

• 8 ounces elbow macaroni
• 6 tablespoons unsalted butter, divided
• 1/2 cup panko breadcrumbs
• 3/4 cup scallions, thinly sliced, divided, plus more, to taste, for garnish
• 1/8 teaspoon plus 1/4 teaspoon kosher salt, divided
• 1/4 cup plus 1/2 tablespoon all-purpose flour
• 3 cups whole milk, warmed
• 1 1/2 cups white cheddar cheese, shredded
• 1 1/2 cups Gruyère cheese, shredded
• 2 cups frozen corn, thawed
• 1/2 cup bacon, cooked and crumbled
• 3/4 teaspoon dry mustard
• 3/4 teaspoon garlic, freshly grated
• 1/4 teaspoon cayenne pepper