Steps
1. Preheat the oven to 350°F (180°C).
2. Cook the pasta according to package instructions, then drain and set aside.
3. In a saucepan, melt the butter over medium heat. Stir in the flour to make a roux.
4. Slowly whisk in the milk until the sauce thickens.
5. Add the cheddar cheese and stir until melted.
6. Season with salt and pepper.
7. Mix the cooked pasta and tuna into the cheese sauce.
8. Transfer the mixture to a baking dish and top with breadcrumbs.
9. Bake for 20-25 minutes until bubbly and golden.
10. Serve hot and enjoy!