1. Peel potatoes; cut into chunks. In pot of boiling salted water, cook potatoes x 20 minutes or until tender. Drain and return to pot; dry over medium heat for 30 seconds.

2. Meanwhile, in skillet, cook bacon over medium-high heat for about 8 minutes or until crisp. Drain on paper towel-lined plate. Chop and set aside.

3. Using a potato masher, mash potatoes, butter, sour cream and salt. Stir in half of the cheese and 1/2 cup of the onions. Scrape into 13x9 inch baking dish; sprinkle with remaining cheese and bacon. (Make ahead: Cover and refrigerate for up to 1 day - then bake for 20-30 minutes before continuing with this recipe).

4. Bake at 400 for about 15 minutes or until cheese melts. Sprinkle with remainig green onions.