Heat oven to 200C/fan 180C/gas 6. Fry the bacon pieces in an ovenproof pan or casserole dish for 3-5 mins until golden and crisp. Stir in the onion and butter and cook for 3-4 mins until soft. Tip in the rice and mix well until coated. Pour over the wine if using and cook for 2 mins until absorbed.
Add the cherry tomatoes and the hot stock, then give the rice a quick stir. Cover with a tightly fitting lid and bake for 18 mins until just cooked. Stir through most of the Parmesan and serve sprinkled with the remainder.
