Peel and cut potatoes into 1 inch cubes. Bring to boil and cook over medium-high heat for 15 to 20 mins. or till tender. Drain. Preheat oven to 350 degrees. Grease/spray 10x12 glass dish or 2 1/2 - 3 qt casserole dish. Return potatoes to pan; Add evaporated milk, sour cream, salt and pepper. Beat with hand mixer until smooth. Stir in about 1 1/2 cups cheese and half of bacon. Spoon into prepared oven dish. Bake for 20 to 25 mins. or until heated through. Top with remaining cheese (I fully cover it), bacon, and green onions. Bake for an additional 3 to 5 mins. or until cheese melts.