Place oil in a 15 by 10 inch jellyroll pan; add potatoes and the next 4 ingredients, tossing to coat. Arrange potato mixture in a single layer.

Bake at 425°F 30 to 35 minutes our 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.