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This Healthy Green Bean Casserole has an unbelievably creamy texture, considering it’s made entirely out of vegetables! It’s ultra-flavorful, and will be a hit at your next holiday meal.

spoonful of healthy green bean casserole

An Alternative to Fried Onions

Instead of topping this healthy green bean casserole with traditional fried onions, this one is topped with caramelized onions. They have all the flavor, without the deep-fried flour!

Since onions can take some time to caramelize, I recommend starting this step first. You can use a separate pan, and just stir the onions every now and then, as they get golden and tender.

caramelized onions in pan

I like to add a splash of water when I see any brown developing on the bottom of the pan. When you add water and stir, the brown should lift up, and give the onions a deep, caramel color. Keep this on low heat while you cook the green beans and mushroom mixture.

Tip: If you miss the crunch that comes from the fried onions, feel free to also sprinkle some sliced almonds over the top.

What’s the Healthiest Way to Cook Green Beans?

Steaming is the best way to preserve nutrients in your green beans, without adding any extra oil. If you’re starting with fresh green beans for this recipe, you’ll want to steam them until they’re fork-tender, about 8 to 10 minutes.

Green beans don’t get significantly softer when you bake them in a casserole, so make sure they are as tender as you want them to be before moving onto the next step.

fresh green beans steamed in white pot

Pro Tip: Use a bag of frozen trimmed green beans if you want to save yourself some time and effort! You’ll still need to cook the beans until they are tender, but they will soften faster than fresh ones.

How to Make Healthy Cream of Mushroom Soup

Traditional green bean casserole recipes call for a can of cream of mushroom soup, but if you’re serving guests who are gluten-free or dairy-free, that won’t work for them. Luckily, you can make your own “cream of mushroom” soup at home!

Sauté the mushrooms and garlic together, until they start to soften, then you’ll add in the parsnips and water. Bring the mixture to a boil, then lower the heat and cover to let the parsnips cook until they’re fork-tender, about 8 to 10 minutes.

If you’d like some whole mushrooms in your final green bean casserole, you can scoop some out now and place them along the bottom of the baking dish. Pile the cooked green beans in there, too!

If you don’t like the texture of mushrooms, transfer them all to the blender, along with the parsnips and cooking water. Add salt and lemon juice, and blend until very creamy.

blended mushroom sauce poured over beans

Pour the creamy “gravy” over the cooked green beans, and toss well to coat. Top the casserole with caramelized onions, then bake until bubbly hot, about 30 minutes.

Make Ahead Tips

This is one of the more labor-intensive recipes on my website, but you can make your life easier by prepping these veggies ahead of time!

Here’s what you can do in advance:

  • Steam the green beans
  • Make the mushroom & parsnip sauce
  • Caramelize the onions

You can store these 3 things separately in the fridge, and on the day of your holiday meal, simply stir the green beans and sauce together, then top with the caramelized onions. Bake at 350ºF until everything is heated through, about 30 to 40 minutes, for a much easier holiday side dish.

healthy green bean casserole with caramelized onions

spoonful of healthy green bean casserole

Healthy Green Bean Casserole (Vegan & Paleo)

4.70 from 30 votes
This Healthy Green Bean Casserole is an easy recipe made entirely out of vegetables! It's gluten-free, dairy-free, soy-free, and totally delicious. Perfect for those on special diets, like vegan & Paleo protocols.
prep40 mins cook30 mins total1 hr 10 mins


  • 1 yellow onion , sliced thinly (269 grams)
  • 2 tablespoons olive oil (10 grams)
  • 1 pound trimmed green beans (fresh or frozen, 16 ounces)
  • 8 oz . mushrooms , chopped (226 grams)
  • 3 cloves garlic , minced (10 grams)
  • 1 cup parsnips , chopped (133 grams)
  • 1 cup water (6 ounces)
  • 1 teaspoon lemon juice (4 grams)
  • 1 teaspoon fine sea salt (6 grams)
  • 2 tablespoons nutritional yeast (optional; 8 grams)


  • Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the onions, and stir until they start to soften, about 5 minutes. Lower the heat, and keep an eye on the onions, stirring every few minutes or so. When you see brown develop on the bottom of the pan, add a splash of water and stir well, so the onions will take on a deeper, caramelized color. You can watch the onions while you prepare the green beans on a separate stove burner.
  • To cook the green beans, fill a pot with 1 inch of water and arrange a steamer basket over that. Pour the green beans into the basket, bring the liquid to a boil, then cover and lower the heat, allowing the beans to steam until fork-tender, about 10 minutes.
    green beans cooking in pot
  • When the beans are done, drain and set them aside. Check on the onions, and give them a stir. In the same pot you cooked the beans in, add in the other tablespoon of olive oil, mushrooms, and garlic. Cook until the mushrooms are soft, about 5 minutes.
    mushrooms cooking in pot
  • To the mushrooms, add in the parsnips and water. Bring the water to a boil, then cover and lower the heat, allowing the parsnips to cook until fork tender, about 10 minutes. At this point, you can also preheat your oven to 350ºF and have an 8- or 9-inch square dish ready.
    parsnips and mushrooms cooking in pot
  • If you'd like some whole mushrooms in the green bean casserole, use a slotted spoon to scoop up several cooked mushrooms and transfer them to the square dish. Add the cooked green beans to the dish, too.
    green beans in casserole dish
  • Transfer the rest of the cooked mushrooms, parsnips, and their cooking liquid to a blender. Add in the lemon juice, salt, and nutritional yeast, if using. (I don't think the yeast is necessary, but it does add extra flavor if you like it.) Blend until smooth.
    mushroom mixture in blender pureed
  • Pour the blended sauce over the green beans in the dish, then stir well to combine. Top with the caramelized onions, which should now be done. Bake for 30 minutes at 350ºF.
    sauce and onions added to casserole
  • Remove the casserole from the oven, and let it cool for 10 minutes before serving. Leftovers can be stored in the fridge for up to 5 days when tightly covered.
    finished green bean casserole with spoon



Nutrition information is for 1 of 9 servings. This information is just an estimate, and not a guarantee.
Make Ahead Tip: If you want to save yourself some time during a holiday meal, you can steam the green beans ahead of time, make the mushroom sauce, and caramelize the onions all in advance! On the day of serving, combine the green beans with the sauce, top with the onions, and then bake until it's heated through and bubbly, about 30 to 40 minutes at 350ºF.


Calories: 73kcal | Carbohydrates: 9g | Protein: 3g | Fat: 3g | Saturated Fat: 1g | Sodium: 266mg | Potassium: 297mg | Fiber: 3g | Sugar: 3g | Vitamin A: 348IU | Vitamin C: 11mg | Calcium: 29mg | Iron: 1mg
Course: Side Dish
Cuisine: American
Keyword: healthy green bean casserole

This recipe was originally posted in 2012, but has been updated in Novebember 2020 to make a more reasonable amount of gravy for the green beans. (The original made twice what you need!) Here are the original ingredient amounts if you need them:

1 yellow onion, sliced thinly
1 tablespoon olive oil
2 cups parsnips, chopped
10 oz. mushrooms, chopped
3 cloves garlic, minced
1/4 cup nutritional yeast
1 1/2 cups water
1 1/2 teaspoons fine sea salt
1 lb. fresh green beans

If you follow the ingredients listed above, you’ll have twice the amount of sauce you need for the green beans, so only use half of it! I think the updated recipe is better, with less of a “parsnip” flavor, but I wanted to make this available, in case it’s been a family favorite for years.

More Healthy Holiday Side Dishes

If you need more healthy holiday recipes, be sure to try these other fan favorites!

When you try this healthy green bean casserole, please leave a comment below letting me know how you like it! And if you make any modifications, I’d love to hear about those, too. We can all benefit from your experience.

Reader Feedback: What’s your favorite holiday side dish?

Megan Gilmore leaning on her white countertop.

Megan Gilmore

Hi, I’m Megan. A former fast food junkie turned best-selling cookbook author. I create healthy recipes made with simple ingredients to make your life easier.

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    1. I would swap it for a small yukon gold potato (about 6 ounces), because that’s what I use in my mushroom gravy recipe and I know it’s delicious!

  1. Yum!!! I love it. Accidentally overcooked the beans, but the delicious sauce makes up for it. As a die hard fan of “regular” green bean casserole, I wasn’t sure I’d love this, but I think it is even better this way! I didn’t have parsnips, so I used a small potato and a carrot. Delicious! I didn’t even need to bake it because the sauce was hot and the beans were cooked; I just put it all together, and it was delicious. Toasted almond slivers were a fantastic idea. 😊 Thank you!

  2. This is an amazing recipe! I’ve made it twice so far, without the parsnips only because I didn’t have any on hand. I will have to try with. Thanks so much for all you do! My foods are limited right now due to health issues and I can find delicious recipes on your site that meet my requirements.

  3. This was pretty good. I think it could have used a little bit more salt or seasonings. Next time I’ll just add some to taste. I’ll definitely make this again though! I made crispy fried shallots to top it with. Yum!