Prick both potatoes with a fork & bake as usual for jacket potatoes. Remove from oven & let cool until you're able to handle them. Slice each potato lengthwise and remove the potato from the jackets, leaving a thin layer of flesh inside each jacket half.

Mash the flesh with butter & milk until all lumps are gone. Finely dice a small amount of onion and add to mash. Add shredded cheese to mixture. Add seasoned salt and a small amount of parsley. Fill all four jacket halves with the mash mixture and top with a sprinkling of seasoned salt.

Bake the halves until the mash begins to brown slightly.