Preheat the oven to Gas Mark 5, 190˚C, fan 170˚C.
Put the fruit in a large shallow baking dish. Sprinkle the sugar and orange juice over the top. Scrape the vanilla seeds out from the pod and add to the rhubarb, along with the pod.
Mix well to distribute the seeds. Roast for 15 minutes until softened, then remove from the oven to cool completely. Spoon the cooled compote into 4 glasses or small bowls. Spoon the yogurt over, then add the granola and drizzle with honey.