Preheat oven to 450 degrees, with rack in center position.
Scrub the potatoes to clean off any dirt, then prick potatoes with a fork. Wrap each in a paper towel and microwave on medium power for 8 minutes per potato. You can bake them in the oven if you prefer by baking at 425, but that takes an hour.
Meanwhile, cook bacon in a large skillet until crisp and transfer to a paper towel-lined plate to drain. Chop bacon and set aside.
Melt butter in microwave for about 20 - 30 seconds. Keep an eye on it and stir it if it starts popping, otherwise it might explode.
Spray or wipe a rimmed baking sheet with cooking oil. Slice the potatoes width-wise 1/4 to 1/2 inch thick. Brush both sides of potato slices with butter and season with salt and pepper, then place potatoes on sheet. Bake until crisp and golden, 10 minutes.
Top with cheeses and bacon and return to oven 5 minutes more, until cheese is melted and bubbly.
Garnish with sour cream and chives and serve immediately.
