Heat the oven to 200C/180C fan/gas 6. Heat half the oil in an ovenproof pan or casserole dish, then stir in the onion and cook over a low heat for 8-10 mins until golden. Scatter over the rice and mix well until coated. Pour over the wine, if using, and cook for 2 mins until absorbed. Pour over the hot stock, then give the rice a quick stir. Put the dish in the oven and bake the rice for 10 mins.

Remove from the oven and stir through the tomatoes, basil, half of the parmesan and some seasoning. Flatten everything out roughly with the back of a spoon, then nestle the chunks of mozzarella evenly into the risotto. Sprinkle over the breadcrumbs and the remaining parmesan, and drizzle with the rest of the olive oil. Put the dish back in the oven, and bake everything for another 10-15 mins until the rice is just cooked through, heating it under the grill if you want a deep, golden crust. Leave to stand for a few minutes, scatter with a few extra basil leaves and serve scooped straight from the dish.