1. Roll the pastry out into a square 80 cm x 80 cm, 2 mm thick and cut into 8 cm x 8 cm squares.
2. Lay the pieces on a tray previously sprinkled with fine semolina and allow to dry for 25 minutes.
3. Heat 5 litres water in a saucepan, add the oil and salt and, when simmering, place in the cannelloni.
4. Move the pieces around very gently while cooking to prevent them sticking and simmer for 8 - 10 minutes until cooked.
5. Refresh under running water until perfectly cold.
6. Lay out a clean cloth on a work surface and arrange the drained and dried pieces of pasta in rows along the cloth.
7. Place the filling into a piping bag with a 1 cm plain tube and pipe 10 g along the leading edge of each piece.
8. Roll up to enclose the filling.
9. Butter a shallow ovenproof dish and place a little of the jus lie at the bottom.
10. Arrange the cannelloni neatly in the dish with the join underneath.
11. Cover with the rest of the hot jus lie.
12. Sprinkle with the grated Parmesan cheese and melted butter and bake in the oven at 180°C until fully gratinated.
Cannelloni may be served with any of the sauces and garnishes associated with spaghetti dishes.