Bake potatoes until done. Cut in half lengthwise. Scoop out pulp and set aside.
Melt butter in heavy saucepan over low heat; add flour, stirring until smooth.
Cook 1 minute, stirring constantly. Gradually add milk, stirring over medium heat
until thick and bubbly. Add potato pulp, salt and pepper, 2 tablespoons of the green
onion, 1/2 cup bacon and 1 cup cheese. Cook until heated thoroughly and stir in
sour cream. Add more milk if necessary (but it should be served thick).
Serve with remaining green onions, bacon and cheese on top.