First things first, cook your baked potato. Preheat the oven to 190ºC. Prick the skins of the potato and spray the outsides with low-calorie cooking spray. Then pop into your oven for 90 minutes.
When your potato is ready, carefully slice it in half. Fluff up the flesh in both halves with a fork, sprinkle over the cheese, and season with salt and pepper. Fluff a little more so it combines.
To a small bowl, add the cabbage, tomatoes, sweetcorn, pepper, and mayonnaise. Mix well, then season to taste with salt and pepper.
Place the potato halves on a plate. Pile on the topping, then sprinkle over the spring onion. Serve!