Preheat the oven to 200C/400F/Gas 6.
For the cannelloni, lightly grease a small ovenproof dish with oil.
Lay the lasagne sheets on a board and divide the ricotta cheese between them, spreading it evenly over them. Scatter the basil leaves over the top of the ricotta cheese.
Sprinkle the grated nutmeg over the lasagne sheets and season with salt and freshly ground black pepper.
Roll the pasta up into cannelloni tubes and arrange in the base of the greased ovenproof dish.
For the sauce, heat the olive oil in a small saucepan and add the garlic. Fry over a medium heat for one minute.
Add the tomato passata to the pan and bring to the boil. Season with salt and freshly ground black pepper. Reduce the heat and simmer for two minutes.
Pour the tomato sauce over and around the cannelloni tubes.
Transfer the ovenproof dish to the oven for 8-10 minutes, or until the cannelloni are heated through and the pasta is cooked.
Serve in the dish.