Heat oven to 375 F.
Leave skin on potatoes.
Scrub and then pierce with fork several times.
Bake the potatoes until tender, about 1 hour.
When potatoes are done, let them cool slightly (leave the oven on).
Cut the potatoes lengthwise in half.
Scoop out inside, leaving a 1/4-inch border of the potato inside the skin.
In a medium bowl, mash the potato flesh until no lumps remain.
Add salt, pepper and sour cream.
Beat until potatoes are fluffy.
Stir in cheese and green onions.
Stuff the potato skins with the filling, mounding an extra on top.
Place on cookie sheet.
Increase oven temperature to 450 F.
Bake for 15-20 minutes.
Sprinkle with reserved chopped green onions and serve.