Preheat the oven to 220 C, Fan 200 C, Gas 7. Line a baking dish with baking paper.
Arrange the fruit cut side up in the lined baking dish and sprinkle with 1 tbsp of the vinegar and the honey or sugar. Roast for 15-20 minutes until the tops of the fruit begin to bubble and char at the edges. Remove from the oven and leave to cool slightly.
Meanwhile in a separate baking dish mix the bread with a good measure of olive oil and a good pinch of salt. Bake for 8-10 minutes until nicely toasted.
In a small bowl mix together the 2 tbsps of olive oil and the remaining vinegar, along with any juices left from roasting the fruit. Add the chilli flakes if using and season with salt and pepper.
Arrange the fruit and bread on a large serving plate and pour over the dressing. Add the mozzarella and bail then drizzle with a little more olive oil and serve.