This green bean casserole with bacon is made with frozen green beans, crispy fried onions, cream of mushroom soup, and crispy bacon. This is the best bean casserole if you're looking for a tasty twist on a classic side dish this holiday season. A traditional green bean casserole is always expected at Thanksgiving dinner, and this version includes salty, sweet, smoky bacon. This bacon recipe is best in an 8x8 or 9x9 casserole dish, or you can double the recipe for a 9x13 casserole dish.