Preheat the oven to 200ºC/gas mark 6. Heat half the oil in a large pan and fry the onion for 5-10 minutes until softened, adding the garlic for the last minute.
Stir in half the basil, the chopped tomatoes, sugar, Worcestershire sauce and the herbs. Bring to the boil, then reduce to a simmer for 10 minutes.
Meanwhile, place the tomatoes on a baking tray, drizzle with the remaining oil and season with black pepper. Oven roast for 10 minutes, until just soft.
Meanwhile, cook the gnocchi according to instructions on the packet and drain. In a small frying pan, lightly toast the pine nuts.
Stir the gnocchi through the tomato sauce. Divide between 4 bowls and top with the pine nuts, roasted tomatoes, remaining basil and parmesan shavings.