Preheat oven to 200 C / Gas mark 6. Lightly oil a baking dish.
Combine spinach, ricotta cheese, egg yolks, garlic, cheddar cheese, nutmeg, 1/2 the herbs, mushrooms, onion, pepper and salt in a large bowl.
Fill dry cannelloni tubes with spinach mixture. Place tubes into baking dish in a single layer. Pour passata over filled tubes ensuring you cover all the pasta. Drizzle over olive oil, sprinkle with freshly ground black pepper and remaining herbs, and sprinkle the reserved cheese.
Cover, either with baking lid or aluminium foil, and bake in preheated oven for approximately 20 minutes. Uncover and bake for a further 20 minutes, or until top is crisp and pasta is tender when tested with a skewer. Serve with garlic bread and a fresh green salad.
Really nice recipe, filled 18 tubes, so plenty for the family. Stuffed tubes using a small spoon and then pushed it down with the handle of a wooden pastry brush, worked perfectly. Going to try it with goats cheese next time. - 09 Sep 2013