Healthy Green Bean Casserole (from scratch!)

Featuring fresh green beans, a homemade mushroom gravy, and delightfully crunchy onions, there is so much to love about this healthy green bean casserole. It’s light, wholesome, and a delicious addition to any holiday menu!

This is a favorite Fit Foodie Finds Thanksgiving side dish. You all have been making it and love it for years!

One of my all-time favorite Thanksgiving recipes is green bean casserole. Growing up, my family used to make it the old-fashioned way with canned green beans, Campbell’s cream of mushroom soup, and crunchy onions (or Funyuns). While there’s nothing wrong with that version, we wanted to give this classic Thanksgiving side a Fit Foodie upgrade with healthy, better-for-you ingredients.

Meet our healthy green bean casserole! It’s just as creamy and still topped with crunchy onions, but everything is homemade with real ingredients. The casserole portion features a from-scratch mushroom gravy that we combine with fresh green beans. The crispy onions bake in the oven and are wonderfully seasoned with parmesan cheese and breadcrumbs.

When combined, this oven-baked green bean casserole has so much savory flavor and is much lighter than the classic. This is a welcome addition to any holiday dinner menu!

What You Need for Healthy Green Bean Casserole

• Fresh green beans
• Mushrooms
• Butter + milk
• Flour
• Broth + salt

Crunchy Onion Topping

Ditch the can of crispy fried onions and top this casserole with real baked crunchy onions. Toss sliced red onions in an egg wash (egg + water) and coat the slices with breadcrumbs, grated parmesan cheese, salt, and pepper. They’ll crisp up as they bake. For maximum crispiness, we recommend broiling them for a few minutes before using them to top the casserole. Don’t skip this step!

Green Bean Casserole Variations

Use our casserole recipe as a starting point and customize it to your liking! Here are a few swaps and substitutions to try:

Mushrooms: Instead of cremini mushrooms, use the same amount of any kind of white mushroom.

Gluten Free: For a gluten free green bean casserole, use certified GF breadcrumbs and GF flour.

Add Bacon: Before serving, sprinkle the baked green bean casserole with cooked, crumbled bacon for a savory twist (similar to our green bean casserole with bacon).

Vegan: Make our vegan green bean casserole for a completely vegan side dish.

Storage

If you have any leftover green bean casserole, store in an airtight container in the refrigerator for up to 3 days.

Make Ahead Healthy Green Bean Casserole Directions

If you plan to make this green bean casserole ahead of time, prepare the mushroom gravy and toss with the uncooked green beans in the casserole dish. Tightly cover the casserole dish for up to 2 days – when ready to bake, follow the instructions in the recipe below. For best results, wait to make the onions until immediately prior to serving so they are perfectly crunchy!

We don’t recommend freezing green beans casserole.

Serving Suggestions

It’s not Thanksgiving without green bean casserole! Add this healthy version to your menu this year – serve it alongside other favorite sides like sweet potato casserole (or mashed sweet potatoes), crockpot mashed potatoes, sausage stuffing, and roasted Brussels sprouts with bacon.

Healthy Green Bean Casserole Recipe

This healthy green bean casserole is made with fresh green beans, homemade mushroom gravy, and delicious crunchy onions.

Prep:20 minutes minutes

Cook:45 minutes minutes

Total:1 hour hour 5 minutes minutes

Fat 10

Carbs 17

Protein 7

Ingredients

For the Onions

• 1 large egg
• 2 tablespoons water
• 1 cup whole wheat bread crumbs*
• 1/2 cup grated parmesan cheese
• 1/8 teaspoon salt
• 1/8 teaspoon ground black pepper
• 2 large red onions thinly sliced (we used setting #4 on the mandoline)

For the Green Bean Casserole

• 1.5 tablespoons olive oil
• 2 cups chopped cremini mushrooms or any kind of white mushroom
• 3 tablespoons unsalted butter
• 1/4 cup white whole wheat flour*
• 1.5 cups 2% milk
• 1/4 cup vegetable broth or chicken broth
• 1/4 teaspoon sea salt divided
• 20 oz. fresh green beans rinsed and trimmed

Instructions 

For the Onions

• In a large bowl, whisk the egg and water together. In a separate smaller bowl, mix the breadcrumbs, parmesan, salt, and pepper together.

• Slice 2 large onions – we used setting #4 on the mandoline (a sharp knife works, too). Add the sliced onions to the bowl with the egg mixture. Stir to coat the onions.

• Add the breadcrumb mixture to the onions. Gently fold everything together until the onions are well coated.

• Spread the onions onto the prepared baking sheet and set aside.

For the Green Bean Casserole

• Place the rinsed and trimmed green beans into the prepared casserole dish. Set aside.

• Heat the olive oil in a large saucepan set over medium/high heat. When the oil is fragrant, add the mushrooms and 1/8 teaspoon of salt. Sauté for 4-6 minutes. Remove the mushrooms from the heat and transfer to a separate bowl. Set aside.

• In the same saucepan, prepare the roux. Melt the butter over medium/high heat. Add the flour to butter and mix until a thick paste forms.

• Slowly pour in the milk while continually whisking the milk, butter, and flour together. Whisk until mixture is thick. Remove the saucepan from the heat.

• Add the broth, cooked mushrooms, and the remaining 1/8 teaspoon of salt to the roux. Mix well.

• Pour the roux over the green beans and toss (directly in the baking dish) so the beans are coated.

• Place both the green bean casserole and onions in the oven at the same time.

• Bake for 20 minutes. Toss the onions and bake for an additional 20 more minutes.

• After 40 minutes, remove the casserole from oven. For extra crispy onions, turn the oven to high broil and broil the onions for 3-5 minutes.*

• Once onions are crunchy, use a spatula to gently transfer onions to top the green bean casserole. Serve warm.

Tips & Notes

• Storage: Store leftover green bean casserole an airtight container in the refrigerator for up to 3 days.
• Make Ahead Instructions: If you plan to make this green bean casserole ahead of time, prepare the mushroom gravy and toss with the uncooked green beans in the casserole dish. Tightly cover the casserole dish for up to 2 days – when ready to bake, follow the instructions in the recipe below. For best results, wait to make the onions until immediately prior to serving so they are perfectly crunchy!
• Breadcrumbs: Plain or Italian breadcrumbs work, too.
• Flour: Feel free to use all-purpose or gluten free flour instead of white whole wheat flour.
• Gluten Free Option: For a gluten free green bean casserole, use certified GF breadcrumbs and GF flour.
• Extra Crispy Onions: This step is optional, but highly recommended. All ovens are different, so make sure to keep an eye on your onions in the broiler!

Nutrition facts

Calories: 176kcal Carbohydrates: 17g Protein: 7g Fat: 10g Fiber: 3g Sugar: 6g