Pre-heat oven to 200 degrees celcius.
Prick potatoes 6-8 times with a skewer or fork.
Wrap potatoes with foil and put onto a baking tray and bake for 45 minutes or until soft.
Meanwhile, combine the tuna, corn, avocado, chives, salt and pepper in a large bowl.
Once potatoes are cooked, cool slightly. Halve potatoes, scoop out flesh and roughly mash potato, saving the skin shells. Alternatively if the potatoes are too small or soft to scoop out, you can cut the top open into quarters and spread it open with a fork.
Add tuna mixture to half the potato mash and spoon the mixture into potato shells. If cutting potato open then just add toppings as is to open potato.
Sprinkle with cheese and bake for 15-20 minutes or until cheese is melted and golden.
Serve with a side salad or bake a tray of your favourite vegetables such as zucchini, pumpkin, red onion, carrot or capsicum with the potatoes in the oven.