The bake time for green bean casserole is only about 30 minutes at 350 degrees, and the prep time isn’t much longer. Our favorite green bean casserole recipe uses cream of mushroom soup and heavy cream to make a quick sauce. Topped with crispy onions and a bit of cheddar cheese, the finished casserole is a creamy, delicious dish that’s sure to be welcome on any holiday table. But why save green bean casserole for a special occasion? It’s easy enough to make for a regular weeknight dinner!