This green bean casserole recipe is a delicious holiday side dish! It's made from scratch with fresh green beans and a creamy mushroom sauce.
Green bean casserole is always on my family’s Thanksgiving menu. We, like many folks, made the classic version with Campbell’s cream of mushroom soup, french fried onions, and canned green beans for years…until I set myself the task of making a homemade green bean casserole from scratch.
Let me introduce you to the results: this green bean casserole recipe. It stars fresh green beans, crispy onions, and a creamy mushroom sauce that blows the canned soup out of the water. Once I tried it, I couldn’t go back to the Campbell’s version, and I don’t think you’ll be able to either.
This green bean casserole recipe is fresh, colorful, and packed with savory flavor. Add it to your holiday table this year, and it’s guaranteed to be a hit.
Green Bean Casserole Ingredients
Here’s what you’ll need to make this recipe:
- Fresh green beans, of course! I like slender haricots verts best, but any type will do. In a pinch, frozen green beans are a fine substitute for fresh.
- Cremini mushrooms – For the homemade mushroom sauce. Swap in white button mushrooms if you prefer!
- Tamari or soy sauce – It brings out the mushrooms’ umami flavor.
- Garlic and thyme – They add fresh, earthy flavor to the sauce.
- Dijon mustard – For tangy flavor.
- Milk (any kind!) and Parmesan cheese – They give the mushroom sauce its creamy texture.
- All-purpose flour – It thickens the sauce.
- French fried onions – They create the casserole’s crispy, savory topping.
- Extra-virgin olive oil – For richness.
- And salt and pepper – To make all the flavors pop!
Find the complete recipe with measurements below.
Variation
Instead of using store-bought french fried onions, make crispy baked onions from scratch! It only takes about 30 minutes, and it’s so delicious. Find the full instructions in the recipe notes below.
How to Make Green Bean Casserole
You can find the complete recipe with measurements at the bottom of this post, but for now, here’s an overview of how it goes:
Start with the onions, if you’re making them from scratch. Tossed with flour, panko, olive oil, and salt, they take about 25 minutes to become crisp and golden brown in the oven.
Then, blanch the green beans until they’re crisp-tender and vibrant green. Drain and spread them on a kitchen towel to dry.
Next, make the sauce. Sauté the mushrooms, then add all the sauce ingredients except the Parmesan. Simmer until thickened, around 20 minutes. Finish the sauce with the cheese and black pepper.
Finally, assemble and bake! Enjoy hot from the oven.
Best Green Bean Casserole Recipe Tips
- Make sure your green beans are dry. No one likes a watery green bean casserole, so dry the green beans thoroughly after you blanch them!
- Watch the onions closely if you’re making them from scratch. They can quickly go from just right to burned, so make sure to keep an eye on them in the oven. I also like to rotate the pans every 10 minutes to help them cook evenly.
Can you make green bean casserole ahead of time?
Yes! You can make this casserole up to a day in advance. Here’s how:
- Blanch the green beans.
- Make the mushroom cream sauce.
- Layer the sauce and green beans in the casserole dish. Cover tightly and store in the refrigerator until just before serving.
- If you’re making the onions from scratch, store them at room temperature for up to 1 day.
- When you’re ready to bake, uncover the casserole and add the onion topping. Bake according to the recipe.
Storage
This recipe is best on the day it’s made, but leftovers keep well for up to 2 days. Store them in an airtight container in the fridge, and reheat in the microwave or a 350°F oven.
More Favorite Thanksgiving Recipes
If you love this recipe, try one of these Thanksgiving side dishes next:
- Best Stuffing
- Mashed Potatoes
- Sweet Potato Casserole
- Cranberry Sauce
- Roasted Brussels Sprouts
- Or any of these 50 Thanksgiving Side Dishes!
Green Bean Casserole
Ingredients
- 1½ pounds green beans, trimmed and halved
- 2 tablespoons extra-virgin olive oil
- 16 ounces cremini mushrooms, sliced
- 2 tablespoons tamari
- 4 garlic cloves, minced
- 2 tablespoons fresh thyme leaves
- ¼ cup all-purpose flour
- 3 cups milk, any kind
- 1½ teaspoons Dijon mustard
- ½ cup grated Parmesan cheese, plus more for sprinkling
- ¼ teaspoon freshly ground black pepper
- 1½ cups french fried onions, or homemade Crispy Baked Onions (see recipe notes)
Instructions
- Preheat the oven to 400°F. Lightly grease a 9x13-inch baking dish.
- Bring a large pot of salted water to a boil and set a large bowl of ice water nearby. Drop the green beans into the boiling water and blanch for 4 minutes. Immediately transfer to the ice water to stop the cooking process. Drain and transfer to a towel to dry.
- Heat the olive oil in a large skillet over medium heat. Add the mushrooms and cook until soft, 8 to 10 minutes. Stir in the tamari, garlic, and thyme. Sprinkle the flour over the mushrooms and stir again. Add the milk and mustard and stir to combine. Simmer until thickened, whisking often, 15 to 20 minutes. Stir in the Parmesan cheese and pepper.
- Spread ⅓ of the sauce at the bottom of the baking dish. Spread the green beans evenly on top, then top with the remaining sauce. Sprinkle on the onions and bake, covered, for 10 minutes. Uncover and bake for 10 more minutes. If the onions start to brown too much, cover the dish for the remainder of the baking time. Garnish with sprinkles of Parmesan, if desired. Serve hot.
Notes
Made according to recipe. Was really really good. Only added a bit of apple cider vinegar and red pepper at the end. Really a nice change from traditional. Thank you.
I’m so glad you loved it!
Hi! Thanks for this great recipe! I’m planning on using my crockpot instead since my small oven will be busy with other dishes….how could I adapt for crockpot? Thanks!
Hi Elizabeth, I’m not sure, I think the mushroom sauce would work fine, but I would recommend baking it in a dish so that the onions get/stay crispy.
I’m planning to make this for Thanksgiving because it sounds like it will taste WAY better than the recipes using canned stuff and I just had a question about the instructions. It says to layer sauce, beans, sauce and I was wondering why you don’t mix the beans into the sauce and then put it all in the dish together and then top with the onions. I’m guessing that it melds together as it cooks, but is there a reason you don’t mix them together beforehand? I feel like you’d get more consistent bean/sauce melding if you did, but I didn’t want to mix them and mess it up if you’ve tried it and gotten better results layering them. I’m sure that presentation-wise, it looks better as written, but I’m not overly concerned about that since no matter what I do, it’s going to look better than the canned version!
Hi Susan, yes, between the sauce on the bottom and top of the green beans, it melds together. If you’d prefer to mix it together first, that would work too.
Can you assemble the night before and cook the next day? Thanks!
Hi Caroline, you can assemble the green beans and mushroom sauce in the baking dish the night before. I’d keep the crispy onions separate at room temperature until you’re ready to bake.
I can’t wait to try this casserole. Which size baking dish is best for these proportions?
Hi Christy, you can use a 9×13 baking dish.
My sister and niece are vegan. The rest of us love Parmesan. Is there a way substitute that will not have an overpowering taste of yeast?
Thank you!
Oops—Is there a way to substitute some other ingredient…
Nooch?
Do I have to use almond milk?
Hi Becca, you can use any milk.
Is there another vegan substitute you could use for the parmesan cheese, as that would help thicken the sauce as well. I might add some mushroom powder, and black salt for umami, but that won’t increase the thickness of the sauce.
Hi!
I’d love to make this for Canadian Thanksgiving and was wondering if this could be made 2 days in advance? We’re travelling and prefer to have it done ahead of time before leaving.
Cheers!
How many cans of cream of mushroom soup should I use – I have many in the pantry that I would like to use up.
Hi there, I know I’m a little late to the game with this recipe, but wondering if you have any suggestions for making it a vegetarian main dish casserole? (By adding protein and starch of some sort…)
Have always loved Green Bean Casserole, but haven’t made it in years because it’s just not Healthy. This recipe was a great find, and has found a permanent home in my recipe box. Thank you!
Hello! Could I sub gluten free flour and bread crumbs to make this a GF dish?
I did and it turned out great
OMG this was delicious!!! Everyone liked it at our Thanksgiving Celebration.
I changed Tamari for Coconut Aminos as we try not to use soy. I also used Almond Flour and Gluten Free Panko to make it Gluten Free. I decided to Omit the Parmesan Cheese as we are dairy free.
It was delicious!!!! Thank you!
Hi Jacky, I’m so glad this was such a hit! Thanks for coming back with your notes about making it gluten free – I’m happy to hear that it was so great with almond flour.
It’s supposed to be thick, not runny – it should be clumpy from the mushrooms, if it’s clumpy otherwise, try sprinkling in the flour slower, while whisking.
I’m having trouble with my onions. I’m following your recipe step by step, but no matter what I do they keep coming out burnt only after 20 minutes. Any suggestions on what I can do to get that golden brown?
Hi Lauren, I wonder if you’re slicing them thinner than I was. I’d try slicing them a tad thicker… if they’re still browning too soon, I’d just take them out early. Ovens can really vary and they’ll finish crisping on the final bake. Hope that helps!
I would try lowering the temp of the oven. Maybe your oven runs hot. One of my ovens does this and I have a hard time with cookies.
Can the whole dish, minus the crispy onions, be made a day in advance, stored in the fridge, and then baked off day of?
Yep, it can!
Hi – I am planning on making this ahead of time since I am traveling and don’t want it to get cold. My understanding is that I can premake everything, assemble it (minus the onions) and then when I get to my destination, I bake for 10 mins covered and 10 mins uncovered as if I was making it all at once? I don’t want to mess anything up! Thanks!
Hi Lauren, yes exactly – once you get to your destination, put the onions on top and bake it!
It was delicious and a huge hit at Thanksgiving dinner, thank you! The onions were burning after 25 minutes, but I was able to salvage most.
Do you use almond milk as a healthier alternative? Could I still use something like whole milk?
Hi Emily, I used it because it’s what I keep on hand. You could use whole milk!
great side dish, a lot of great ingredients that all meld together, thank you
We are a mushroom-free household. In recipes that have called for cream of mushroom soup, I’ve always substituted a different cream soup (celery, potato, even tomato when it wouldn’t be bizarre). Any suggestions for alternatives in this recipe?
Hi Janet, any of those subs would work in this recipe as the sauce component, if you prefer.
Any suggestion for substituting for the mushrooms and keeping the rest of the filling recipe? I would rather make something fresh rather than use a canned soup…
Hi Janet, mushrooms are the main ingredient of the sauce so I don’t have a substitution for them in this recipe.
I would try riced cauliflower browned in butter. Wouldn’t give the mushroom flavor, but I think it would fill in nicely.