Preheat the oven to 200°C/400°F/Gas 6.
Pierce the potatoes with a fork, then bake for 1 hour, or until soft on the inside with a lovely crisp skin.
Meanwhile combine all the other salad ingredients in a large salad bowl.
Remove the potatoes from the oven. Leave to cool for 10 minutes, then cut into chunks and add to the salad.
Toss all the ingredients together.
Serve with the vinegar and oil on the side so you can add to taste.