Preheat the oven to Gas 4, 180°C, 350°F.
Place the rhubarb in a saucepan with the sugar and 300ml of water. Simmer for 5 minutes or until the rhubarb starts to soften. Add apple and cook for 2 minutes. Add pear and cook for 1 minute or until the fruit is tender, stirring gently. Remove from heat and cool.
Place the dried fruit in an ovenproof dish, add the rhubarb, apple and pear and the cooking liquid and gently stir. Cover the dish and bake for 20 to 25 minutes until the fruit has softened. Serve warm or chilled with a dollop of yogurt.