Tuna, Corn and Mayo Baked Potato

• 2 large brushed potatoes
• 1 tbsp extra virgin olive oil
• 185 g tinned tuna chunks in oil
• 2 tbsp mayonnaise
• 2 tbsp Greek yoghurt
• 0.125 tsp salt
• 0.125 tsp pepper
• 0.25 red onion, finely chopped
• 200 g tin corn kernels, drained
• 0.333 cup grated cheese
• 3 cup rocket
• 1 tsp balsamic dressing