Preheat oven to 425 degrees F. In a resealable plastic bag, toss potatoes with oil, salt, and pepper. Spread evenly onto baking pan and cover with foil. Bake for 30 minutes, remove cover and turn potatoes. Bake for 10 additional minutes or until lightly browned.
For the sauce, heat oil in medium saucepan. Add flour and stir over medium heat for 30 seconds. Add milk and stir until thickened. Reduce heat to low; stir in cheese, green onions, bacon bits, and pepper. Serve potato wedges with warm cheese sauce.