Cook 6 bacon slices in advance in the oven or in a frying pan. Lay on a paper towel to absorb excess grease, then use kitchen scissors to chop and crumble small.
Wash and scrub the russet potatoes. Cut into 1" slices.Place the potato slices in a large bowl. Fill and cover them with enough hot water (I used a kettle to boil water). Let soak for 10 minutes.Drain the potatoes then wrap in a clean kitchen towel to dry off. Make sure each potato has been individually dried. Less water = crispier potatoes!
Preheat the oven to 375°F.Place each slice on a baking rack or baking sheet in a single layer so that they're not touching eachother. Spray the tops with cookign oil spray. Season with salt and pepper.Bake for 40-50 minutes or until potatoes are soft on inside and outsides are cripsy golden brown.
While potatoes are baking, prepare the toppings: grated cheddar cheese, crumbled bacon, diced green onions, and sour cream.
Remove slices from oven and check for doneness by poking with a fork.Sprinkle the tops with cheese and bacon. Bake an additional 2-3 minutes.
Remove from oven and top with sour cream and green onion. Serve while still warm.