Preheat oven to 375°
Wash potatoes and dry. Cut each potato into 1/2 thick slices and place on a cookie sheet.
Brush each slice with olive oil and top with salt & pepper.
Bake for 25 minutes.
While potato slices are in the oven, cook bacon until crisp, drain on paper towels. Reserve bacon fat in the pan.
Chop bacon and set aside.
Remove potato slices from the oven. Baste both sides of each slice with the reserved bacon fat and season with salt & pepper.
Return potato slices to the oven and bake for an additonal 10 minutes.
Check doneness by pricking slices with a fork, they should be lightly browned on top and soft on the inside.
Remove potato slices from the oven and top each slice with a sprinkle of Ranch seasoning, a teaspoon of crumbled bacon and some cheddar cheese.
Return to the oven and bake for about 3-5 minutes until cheese is melted and bubbly.
Turn oven to broil and cook until cheese is lightly browned along the edges. Watch closely so they don't burn, this will only take a minute or two.
Serve slices topped with a sprinkle of chives or green onions and a generous dollop of sour cream.