Preheat oven to 200C. Score the potatoes lengthways around the middle and bake for one hour. Then scoop out the flesh leaving just about a millimetre against the skin (if you like you can use the leftover flesh for, say, fishcakes or in a soup).

Place the hollow skins upside down on a baking tray, bush with olive oil and put them back in the oven for a further 10 minutes until crisp. Meanwhile, in a bowl, toss all the other ingredients together until they are thoroughly mixed. Check the seasoning and adjust. When the skins are done, just ladle a spoonful or two of the mix into each skin.