Divide the filling among all the hollowed-out potatoes. Using the same cookie sheet you roasted them on, bake the potatoes in the oven until the tops are golden brown. Remove and garnish with chives.
Preheat the oven to 350 F.
In a small saute pan over medium-high heat, cook the bacon until crispy. Cool and then chop. Place the potatoes in a bowl and drizzle with EVOO, salt and freshly ground black pepper. Bake in the oven on a cookie sheet for 45 minutes to an hour until they are cooked through; you may have to rotate the pan so they brown evenly. Remove from the oven. When cool enough to handle, cut a thin lid from the top of each potato. Using a small teaspoon or melon baller, scoop out the inside of the potato, leaving a half-inch border from the edge.
Remove all the potato "guts" and lids to a medium-size mixing bowl. To the bowl, add the milk, butter, sour cream, cheese, reserved bacon, salt and freshly ground black pepper. Mix to combine.