In a large saucepan bring the vegetable stock to a simmer. While the stock is heating drain the sun-dried tomatoes and reserve the oil. Chop the tomatoes coarsely and set them aside.
In a large frying pan warm 2 tablespoons of oil from the tomatoes then add onion and saute until translucent; about 6 minutes.
Add rice to the frying pan and stir until white spots appear in the centre of the grains; about 1 minute. Spoon a ladleful of vegetable stock into the frying pan and cook the mixture on low until all the stock is absorbed; about 2 minutes. Continue adding the stock a ladleful at a time until the rice is tender and the mixture is creamy; approximately 20 to 25 minutes.
Add the mozzarella cheese, Parmesan cheese, sun-dried tomatoes, 2 tablespoons of the remaining oil from the tomatoes, diced basil, salt and pepper. Mix well and serve.