Preheat the oven to 425 degrees F.
Put the beans on 1 or 2 baking sheets. Sprinkle over the bacon and onions, and add the olive oil, salt and pepper. Toss around to mix and coat everything in oil.
Bake until the bacon is sizzling and the beans are starting to brown, 18 to 20 minutes.
Recipe courtesy of Ree Drummond