1. Pre-heat the oven to 160°-170°C (Gas Mark 3).
2. Thoroughly wash and scrub the potato.
3. Using a dinner fork, prick the potato several times and place on a baking tray.
4. Sprinkle the potato with a little sea salt and place in the pre-heated oven.
5. Cook until the potato is soft when squeezed with your fingers.
6. A little care should be taken when testing your potato as they can explode, so always cover your potatoes with a clean cloth before testing with your fingers.
7. The cooking time will differ from each type of potato and, of course, depending on the size of potato.
8. On average they take around 60 to 75 minutes.
9. When cooked, remove baked jacket potato from the oven and allow the potato to rest for a few moments.
10. Cut a large cross on the top of the jacket potato and squeeze from the middle with your fingers. This will force the baked potato to open.
11. Season to taste, place a large knob of butter into the potato and serve.