Preheat the oven to 220C/200 fan/428F/Gas mark 7. Prick the sweet potato, put on a baking tray and place in the oven. Cook until soft inside – about 50 minutes.
Place the salad leaves on a plate, add the cherry tomatoes and beetroot, pour over the salad dressing. Open the sweet potato and mash in the butter, add to the plate and enjoy.