Cheesy Green Bean and Mushroom Casserole
A Fancified Classic
For several years now, I’ve been experimenting with making the best green bean casserole possible. The classic version is a crowd favorite, but I always knew it could be better. I was craving more texture, punchier flavors, and fresher ingredients. And, friends, this is it. This cheesy green bean casserole takes a few extra minutes than opening cans and dumping ingredients into a pan, but the time is absolutely worth it. The skinny, fresh green beans are so fresh and tasty, the texture of the mushrooms is everything, the onions and garlic give it a way more interesting base, and the layers of melty cheese will have you craving more from the first bite.
For the purists out there, this cheesy green bean casserole is still reminiscent of the classic. It contains all of the original flavors, like the cream of mushroom soup and the crispy fried onions that will make you reminiscent of Thanksgiving's past. This version essentially intensifies all of those perfect flavors - close your eyes, and you may just think this was made with lots of extra love.
Tips For Making This Green Bean and Mushroom Casserole
If you plan on making this fancy green bean casserole, here are a few tips to make sure you’re successful:
- If you can’t find haricot verts (the thin version of fresh green beans), you can use fresh or canned green beans. If using fresh, be sure to trim the ends before cooking them. If using canned, reduce the cook time on the stove by half, as they will already be softened.
- If havarti and gruyere are hard to find at your local grocer, here are a couple substitution options for each: For the havarti, switch with another soft, melty cheese like mozzarella or fontina. For the Gruyere, a sharp cheese like swiss or emmental will work great.
- While havarti is easily melted, the soft texture can make it hard to grate. To help make it easier to grate, throw it in the freezer 30 minutes before you try to shred it. This will firm up the cheese a bit, making it easier to run along the cheese grater.
Recipe Details
To prepare this green bean and mushroom casserole, you’ll first prepare your fresh vegetables and aromatics (the onions and garlic) on the stove top. Once you’ve melted butter in the pan with some olive oil, you’ll saute thinly sliced white button mushrooms until they’re lightly browned and very soft. To the mushrooms you’ll add an aromatic base of yellow onion and garlic. These flavors will uplevel the entire dish and reinforce the oniony flavor from the classic fried onion pieces. To this base you’ll toss in haricot verts style green beans, letting them cook until they are fork tender. The haricot verts style green beans are a bit thinner and crisper, giving the end dish a really nice texture!
To the cooked veggies, you’ll mix in the cream of mushroom soup, a bit of water to thin it out, and the crispy fried onion pieces. Half of the green bean mixture is then transferred to a casserole dish and topped with lots of shredded fontina, gruyere, and parmesan cheese. This gives the dish a cheesy center and ensures each bite gets a melty cheesy bite. The remaining green beans are added on top, followed by the remaining cheese and some more fried onion pieces.
Bake the cheesy green bean casserole for about 15 minutes, until the cheese is melty and the soup mixture begins to slightly bubble. This stage means the flavors have melded together into one delicious bite! Let the casserole cool on a cooling rack for 5 minutes and then serve to your guests to enjoy!
For the holidays, this is an easy one to make ahead. Once you transfer everything to the casserole dish, let cool on the counter for 15-30 minutes and then wrap in plastic wrap and transfer to the refrigerator up to one day in advance. Before serving, add to a 375°F oven for 20 minutes until the cheese is melty and the green beans are warmed through. In addition, you can keep this warm on a table top warmer or in a 200°F warming draw until ready to serve.
If you like the sound of this recipe, you should also check out these side dishes to round out your meal:
- Nana’s Corn Souffle
- Pumpkin “Cheese” and Cauliflower
- Persimmon Salad with Burrata, Dried Cranberries, Bacon, and Walnuts
- Curry Carrot Pumpkin Soup
Be sure to tag @laura.loves.to.cook on Instagram, TikTok, or Facebook to let me know how your recipes turn out. I hope you love it as much as I do!
A fancified version of the classic holiday side dish, this cheesy green bean casserole uses fresh green beans, sauteed mushrooms, extra aromatics, and loads of melty cheese. It’s sure to impress anyone at your dinner table.
- 2 tbsp unsalted butter
- 1 tbsp olive oil
- 10 oz white button mushrooms, thinly sliced
- 1/4 whole yellow onion, diced
- 3 cloves of garlic, minced
- 24 oz haricot verts style green beans, cut in half
- 1/2 cup water
- 11 oz cream of mushroom soup
- 1 1/2 cup fried onion pieces, divided
- 6 oz fontina cheese, shredded
- 6 oz gruyere cheese, shredded
- 2 tbsp grated parmesan cheese
Preheat your oven to 375°F and set out a 9x13 casserole dish.
In a large saute pan, melt the butter and warm the olive oil over medium-high heat. Add the sliced white mushrooms and toss into the fats. Saute until lightly browned and soft, about 5-7 minutes.
Add the chopped yellow onion to the pan and toss into the mushrooms. Continue to saute until the onions are softened, about 3 minutes.
Add the minced garlic to the pan and saute until fragrant, about 30 seconds.
Reduce the heat to medium and add the haricot verts style green beans to the pan and toss with the aromatics and mushrooms. Let cook, carefully stirring every 2 minutes, until the green beans are fork tender, about 10 minutes. Once cooked, take off the heat.
To the saute pan, add the water and cream of mushroom soup. Toss to coat the green beans and vegetables with the soup and to integrate the water. Stir in 1 cup of the fried onion pieces until evenly distributed.
Spoon half of the green bean mixture into your 9x13 casserole dish. Sprinkle 3 oz of the shredded fontina, 3 oz of the gruyere cheese, and 1 tablespoon of the grated parmesan cheese.
Add the remaining half of the green bean mixture into the casserole dish. Top with the remaining fontina, gruyere, and parmesan cheese. Sprinkle the remaining ½ cup of fried onion pieces.
Bake the casserole in the oven for 15 minutes, until the cheese is melty and the soup mixture begins to lightly bubble.
Let cool on a cooling rack for 5 minutes and serve. Enjoy!
