Preheat oven to 450. Cut the potatoes into 1/4 inch slices. Brush both sides of the potatoes with oil. Place rounds on a baking stone or sheet pan. Bake for 20 minutes or until lightly browned. Remove from the oven.
Meanwhile cook the bacon until crisp, drain and crumble. In a medium bowl combine bacon, cheese and sliced green onions in a bowl and toss together.
With a basting brush, brush each potato rounds with barbeque sauce. Sprinkle the cheese mixture on top. Return to the oven. Bake 3-5 minutes until the cheese is melted.