Arrange bacon slices on an oven safe rack placed inside a baking sheet lined with foil for easy cleanup. Bake 5 to 7 minutes depending on the thickness of your bacon. (It should be starting to brown, but still be pliable when you remove it from the oven.) Remove from oven and set aside. Leave oven on.
Meanwhile, place green beans in a large steamer basket over a large pot of boiling water. Cover and steam 3 minutes, until just bright green. (This step will help preserve the color and texture of the green beans when roasting.) Transfer green beans immediately to a large bowl. Drizzle with olive oil and season with salt and pepper; toss to coat evenly.
Divide green beans into 12 bunches of 8 to 10 beans. Starting about an inch below the tips, wrap each bundle with 1/2 slice of bacon, pressing or tucking under ends to secure and taking care to minimize areas where bacon overlaps. Arrange bacon wrapped green bean bundles, seam side down, in a single layer on same oven safe rack in baking sheet, leaving some space between each.
Bake in preheated oven 15 to 18 minutes, until bacon is crisp. Serve.