Preheat your oven to 375°F. Grease a 9-inch by 13-inch baking dish, and set it aside.
First, blanch the green beans.
Bring a large stockpot of salted water to a boil, and add the prepared fresh green beans. Boil until the beans are bright green and almost fork tender (about 3 minutes).
Drain the beans of the water, and scatter on clean paper towels to drain.
Blot the beans dry, return them to the large stockpot or a large bowl, and set it aside.
Pour the cream of mushroom soup over the blanched green beans. Stir gently to coat the beans in the cream sauce (without crushing any of the beans). Add about 3/4 of the optional grated cheese, and mix to combine.
Pour the entire contents of the stockpot into the prepared 9-inch by 13-inch baking dish. Spread into an even layer, and then scatter the remaining mushrooms on top in an even layer. (See Recipe Notes)
Sprinkle about half of the remaining optional cheese on top of the mushrooms.
See Recipe Notes for make-ahead instructions.
Make the topping.
In a small bowl, combine the bread crumbs with the melted butter, and stir to combine.
Scatter the bread crumbs evenly over the top of the green bean mixture in the baking dish. Top with the remaining optional cheese.
Place the baking dish in the center of the preheated oven, and bake until the topping is lightly golden brown and the sauce is bubbling (about 15 minutes).
Remove from the oven and top with the crushed crispy fried onions. Press the onions down gently, and serve immediately.
Preparing the green beans. You can trim the ends of your green beans cleanly in one cut, or leave them intact. You can slice the green beans in half by cross-section, to make serving easier, or leave them whole.Make ahead option. At this point, the dish can be cooled to room temperature, then covered tightly and stored in the refrigerator for 2 to 3 days. Before serving, just resume the recipe instructions where you left off.Originally published on the blog in 2013. Recipe modified slightly to incorporate recipe for gluten free of mushroom soup by reference; photos mostly new.
Easy Gluten Free Green Bean Casserole | No Canned Soup! from Nicole Hunn at Gluten Free on a Shoestring. Find recipe online at https://glutenfreeonashoestring.com/gluten-free-green-bean-casserole/