Preheat oven to 180?C.

Heat the oil in a medium ovenproof frying pan or casserole dish over medium heat. Add the onion and cook for 1-2 minutes or until just starting to soften. Add pancetta and cook for 2 minutes. Add the chicken and garlic, and cook, stirring, until chicken is lightly browned. Stir in the rice, tomato passata and 500ml water. Season with salt and pepper and bring to the boil. Cover the pan with a lid or some foil and place in preheated oven to bake for 30 minutes or until most of the liquid has been absorbed. Stand the pan, covered, on the bench for 5 minutes to absorb excess liquid. Stir in the basil.

Preheat grill to high. Place the brie, slightly overlapping, on top of the rice and place under the grill for 5 minutes until the cheese starts to melt and turn golden. Garnish with the basil leaves.