Steps
1. Preheat oven to 350°F (180°C).
2. Cook pasta according to package instructions, then drain.
3. In a saucepan, melt butter over medium heat. Stir in flour until smooth.
4. Gradually whisk in milk until the sauce thickens.
5. Add half of the cheese, stirring until melted.
6. Mix in tuna and cooked pasta, season with salt and pepper.
7. Transfer the mixture to a baking dish, top with remaining cheese.
8. Bake for 20 minutes or until cheese is bubbly and golden.
9. Serve hot and enjoy!