Preheat oven to 180°C.
Thoroughly scrub the potatoes in cold water, using a brush to remove any dirt. Pierce the skin of the potatoes all over with a fork.
Place the potatoes in a bowl and coat with oil and a sprinkle of salt.
Place potatoes on a baking tray and bake for 50 minutes or until soft in the centre.
Top with tuna and bean mix and grated cheese.
Bake in oven for a further 15 minutes until golden brown.
Serve topped with yoghurt.