Heat oven to 190 C and oil a large baking dish.
Spread a thin layer of bechamel in the dish.
Pipe or spoon the beef filling into the cannelloni shells and nestle them in one snug layer.
Cover with the rest of the bechamel then scatter mozzarella and the rest of the parmesan.
Bake for 30 to 35 minutes until the top is golden and the sauce bubbles at the edges.
Rest for 10 minutes then serve with a green salad.