Green bean casserole is a classic Thanksgiving side dish that is a regular at any holiday table. I put a fresh twist on this traditional side that will have even the green bean casserole disapprovers changing their mind. This recipe for sheet pan green bean casserole has roasted green beans that don’t get mushy, a fresh homemade creamy mushroom sauce, and of course gets topped with plenty of everyone’s favorite French-fried onion strings! This updated version of green bean casserole is easy to make, and you are going to love the fresh flavors.