The only green bean casserole recipe you'll ever need! Fresh green beans, crispy baked onions & a creamy mushroom sauce make it a guaranteed hit.
I’ve had a green bean casserole recipe on my list to make for years. It’s a staple at my family’s Thanksgiving, and in theory, it’s a dish that’s all about veggies: it features a creamy mushroom sauce and loads of crispy onions, and green beans are the star of the show!
Like sweet potato casserole, it was a natural candidate for a Love and Lemons recipe made with whole foods ingredients. For so long, one thing or another would bump it off my list – a Brussels sprouts kick, my favorite Butternut Squash Stuffed Shells, or even just really good green beans on their own. But this year, I finally got down to working on my own green bean casserole recipe, and I have to say that the results are pretty fantastic!
Green Bean Casserole Recipe Components
Jack and I both adore mushrooms, so I swap the traditional cream of mushroom soup for a tangy, creamy homemade mushroom sauce. Mushrooms, thyme, and Dijon mustard are one of my all-time favorite combinations, so of course, I use them here, along with tamari to enhance the mushroom flavor and Parmesan cheese for an umami punch. I think you’ll love this sauce – it’s so good I could eat it straight off a spoon!
Then, instead of canned or frozen green beans, I use fresh ones. I blanch them before baking them in the casserole, and they come out vibrant green with a nice al dente bite. Yum!
And last but not least, I replace the usual canned French fried onions with a big pile of crispy baked onions. With a delectable oniony flavor and crisp texture, these guys are the perfect finishing touch for this healthy green bean casserole. Tip: Make sure you get a little of everything in each bite!
How to Make Green Bean Casserole
This green bean casserole recipe has three components: the crispy onions, the green beans, and the mushroom sauce.
Start with the onions. Slice the onions into thin half-moons and toss them with olive oil, flour, salt, and panko. Spread them in an even layer on two large baking sheets and roast until they’re golden brown and beginning to crisp up, tossing them every 10 minutes.
Then, blanch the green beans. Bring a large pot of salted water to a boil and add the green beans. Cook for 4 minutes, stirring occasionally, until the beans are slightly tender and vibrant green. Drain them, and transfer them to a large bowl of ice water to stop the cooking process. After they’ve cooled, spread them on a kitchen towel to dry.
Next, make the sauce. Sauté the mushrooms until they’re soft, and stir in tamari, garlic, and thyme for flavor. Sprinkle in some flour, and add almond milk and Dijon mustard. Simmer until thickened, around 20 minutes. Then, stir in Parmesan cheese and black pepper.
Finally, layer everything together, and bake! Cover the bottom of a greased baking dish with a thin layer of the sauce. Pile in the green beans, and spread the rest of the sauce on top. Sprinkle the crispy onions on top, and bake, covered, for 10 minutes. Uncover the baking dish, and bake for 10 minutes more.
Best Green Bean Casserole Recipe Tips
- Look for haricots verts. Any type of fresh green beans will work in this recipe, but we had the best results with thin haricots verts. They’re slimmer than regular green beans, which helps them integrate with the sauce and onion topping. Plus, they have a delicious snappy texture!
- Watch the onions as they cook, and rotate the pans. When you toss the onions every 10 minutes as they cook, rotate their baking sheets. This will help ensure even cooking – you don’t want one pan to burn before the other gets crispy! Watch them closely near the end of the cooking time, as they can quickly go from just right to burned.
- Make sure your green beans are dry. No one likes a watery green bean casserole, so make sure to dry the green beans thoroughly after you blanch them!
- Make it ahead! You can make this green bean casserole up to a day in advance. Bake the crispy onions, blanch the green beans, and make the sauce. Then, assemble the casserole with the sauce and the green beans, cover, and refrigerate until just before serving. Store the crispy onions separately at room temperature. When you’re ready to eat, layer on the crispy onions, and proceed with the recipe, baking the casserole until it’s heated through. Enjoy!
More Favorite Thanksgiving Recipes
If you love this green bean casserole recipe, try one of these delicious side dish recipes next:
- Butternut Squash Soup
- Maple Roasted Acorn Squash
- Creamed Spinach
- Roasted Garlic Mashed Potatoes
- Kale Salad with Carrot-Ginger Dressing
- Roasted Brussels Sprouts
- Simple Roasted Beets with Citrus
- Roasted Delicata Squash with Apples and Sage
- Simple Baked Sweet Potatoes
- Thanksgiving Stuffing
- Best Pumpkin Pie
- 50 more Thanksgiving Side Dishes
Green Bean Casserole
- 2 medium yellow onions, thinly sliced
- 4 teaspoons extra-virgin olive oil
- ½ cup all-purpose flour
- 2 tablespoons panko breadcrumbs, plus more for sprinkling
- ½ teaspoon salt
- 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 unsweetened almond milk
- 1½ teaspoons Dijon mustard
- ½ cup grated Parmesan cheese, plus more for sprinkling
- ¼ teaspoon freshly ground black pepper
- Make the crispy onions: Preheat the oven to 450°F. Line 2 large baking sheets with parchment paper and lightly grease a 9x13-inch baking dish.
- In a large bowl, toss the onions with the oil, flour, panko, and salt. Spread evenly onto the baking sheets and bake for 25 to 35 minutes, tossing every 10 minutes (rotating the pans in the oven as necessary), until lightly browned and crispy. Remove from the oven and lower the oven temperature to 400°F.
- Prepare the filling: 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. Drain, and immediately immerse in the ice water to stop the cooking process. Drain, and transfer to a towel to dry.
- Heat the olive oil in a large skillet, 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 almond milk and mustard and stir to combine. Simmer until thickened, whisking often, for 20 minutes. Stir in the Parmesan cheese and pepper.
- Spread ⅓ of the sauce into the baking dish. Layer with green beans and top with the remaining sauce. Sprinkle the onions on top and bake, covered, for 10 minutes. Uncover and bake 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 panko and Parmesan, if desired. Serve hot.
Crispy onion method inspired by Ambitious Kitchen and Alton Brown.
Way too salty. Threw it out and made lemon green beans. A lot of work and almond milk wasted. Would not recommend. The tamari is too much..
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?
Oops—Is there a way to substitute some other ingredient…
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.
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.
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.
The sauce was really thick and clumpy. Is it supposed to be that thick or more runny? I probably need 15 minutes vs 20.
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.