Preheat oven to 400.

Mix onion and milk and let stand at room temperature until Potato's are done.

Scrub Potato's with a vegetable brush or new plastic pot scrubber until clean and skins are almost transparent. Pierce with a fork in several places. Bake about 1 hour or until done.

Cut Potato's in half lengthwise and scoop out insides, leaving about 1/4 inch of potato behind, reserve shells.

Mash Potato's and beat in butter, milk mixture, salt, parsley and half of the cheese. Spoon mixture back into shells and sprinkle remaining cheese on top.

Return to oven for ten minutes or until cheese is melted and slightly browned.