1) Preheat the oven to 220°C/gas mark 8.
2) Place the peaches and plums snugly in a single layer, cut side up, in 2 glass or porcelain oven-proof baking dishes. Sprinkle with the sugar, and then top with the raspberries. Bake for 20 to 25 minutes, until tender.
3) Heat the grill and place the fruit about 5 inches below the heat and grill for 5 to 8 minutes, until the berries release some of their juices.
4) Remove from the oven and sprinkle with orange juice. Serve warm, at room temperature, or chilled.