Gather all ingredients.
Prick potatoes with a fork and cook in the microwave, 3 or 4 at a time, until fork-tender, about 7 to 8 minutes. When cool enough to handle, scoop out the flesh.
Melt butter in a large saucepan over medium heat; stir in flour and cook until well combined, about a minute. Whisk in milk, a little at a time, stirring constantly until thickened.
Stir in cooked potatoes, salt, pepper, ⅓ cup bacon bits, 2 tablespoons green onions and most of the cheese. Cook until thoroughly heated. Stir in sour cream and heat through.
Serve topped with remaining bacon, onions and cheese.
