Crispy Croque Monsieur with Breadcrumbs

Method

1. Preheat oven to 375°F (190°C).
2. Butter both sides of bread slices.
3. Layer ham and Swiss cheese on one slice of bread.
4. Spread Dijon mustard on the other slice and place on top.
5. In a saucepan, melt butter, add flour, and gradually whisk in milk until thickened.
6. Stir in grated Parmesan and breadcrumbs, then season with salt and pepper.
7. Pour the mixture over the sandwich and bake for 15-20 minutes until golden.