Place oil in a 15- x 10-inch jellyroll pan; add potatoes and the next 4 ingredients, tossing to coat. Arrange potato mixture in a single layer.
Bake at 425° for 30 to 35 minutes or until potatoes are tender, stirring occasionally. Transfer to a large bowl.
Toss together potatoes, bacon, green onions, and dressing. Add salt and pepper to taste. Serve immediately or cover and chill until ready to serve.