Pierce potatoes using a fork or skewer. Place on a baking tray and brush with oil. Bake in a preheated oven at 190°C for 1 hour or until tender. Allow potatoes to cool enough to handle and cut in half lengthways.
Scoop out and reserve the potato flesh leaving a 1cm shell. Return potato halves to oven tray. Combine reserved potato flesh, John West Sardines, parsley, Edgell Corn Kernels and parmesan cheese in a medium bowl. Divide potato mixture between potato shells. Sprinkle with extra parmesan cheese.
Bake potatoes in a preheated oven at 190°C for 10 minutes or until cheese is melted and lightly browned.