Bake the potatoes until they are done, carefully scoop pulp out while still hot and set aside.
In a medium size skillet over medium or medium high heat melt butter.
Gradually add flour while stirring to make a roux.
Once flour and butter are mixed together gradually add the milk, stirring constantly until mixture is thickened and bubbly.
Add potato pulp, salt and pepper.
Cook until heated through.
Turn the stove top down to low and add sour cream.
Cook for another 5 minutes.
Add extra milk if too thick for your liking.
Garnish with cheese, bacon and green onions.