1. Preheat your oven to 375°F or 190°C.

2. Cook the pasta according to the package instructions until it reaches the al dente stage then drain and set aside.

3. In a large saucepan melt the butter over medium heat then whisk in the flour and cook for one to two minutes until lightly golden.

4. Gradually pour in the milk whisking continuously to avoid lumps then bring the mixture to a boil and reduce the heat to low and simmer for five minutes until thickened.

5. Take the sauce off the heat and stir in the grated cheese salt and pepper until the cheese is fully melted and the sauce is smooth.

6. In a separate pan warm the meatballs over low heat.

7. In a large mixing bowl combine the cooked pasta warmed meatballs and bechamel sauce then toss everything together until the pasta is well coated.

8. Transfer the pasta mixture to a baking dish and add extra grated cheese on top if desired.

9. Bake the gratin in the preheated oven for twenty to twenty-five minutes until the top is golden brown and the sauce is bubbly.

10. Take the gratin out of the oven and let it rest for a few minutes before serving.