Name: Healthy Green Bean Casserole
Prep time: 15 min
Cook time: 55 min
Total time: 1 h 10 min
Cuisine: American
Ingredients: Green Beans:; 2 pounds green beans, trimmed; Kosher salt; Crispy Onion Topping:; 1 tablespoon olive oil, plus more for greasing; 1 onion, thinly sliced; 1/2 cup almond flour or gluten-free breadcrumbs; 1/4 cup freshly grated Parmesan cheese, or nutritional yeast + 1/2 tablespoon lemon juice; 2 tablespoons chopped fresh parsley, plus more for garnish; 1/2 teaspoon kosher salt, plus more to taste; Creamy Mushroom Sauce:; 2 tablespoons olive oil; 8 ounces baby bella (cremini) mushrooms, thinly sliced; 4 cloves garlic, minced or grated; 1 teaspoon fresh thyme leaves; 3 tablespoons 1:1 gluten-free flour or white whole wheat flour; 1 3/4 cups dairy milk, almond milk, or cashew milk; 1 teaspoon kosher salt, plus more to taste; 1/2 teaspoon black pepper; 1/8 teaspoon ground nutmeg; 7 ounces Greek yogurt or non-dairy yogurt (about 3/4 cup); Flaky sea salt, for garnish

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This Healthy Green Bean Casserole is a wholesome take on the traditional holiday side dish, made entirely from scratch—no canned soup or fried onions required. Featuring tender-crisp green beans, a creamy homemade mushroom sauce, and a crunchy onion topping, this dish delivers on comfort while keeping things light, gluten-free, and with a dairy-free option included.

Healthy Green Bean Casserole

Why You’ll Love This Recipe

No processed ingredients – Made from scratch with whole, real-food ingredients.
Gluten-free and dairy-optional – Easily adapted for various dietary needs.
Lighter than the classic – Still rich and satisfying, but without the heaviness.
Creamy and crunchy – Perfect balance of textures with velvety sauce and crisp topping.
Holiday favorite made healthier – All the nostalgia with none of the guilt.
Packed with flavor – Garlic, thyme, nutmeg, and Parmesan (or nutritional yeast) build a deep, savory taste.
Easy to prepare ahead – Can be prepped in parts and assembled later.
Vegetarian-friendly – A meatless side that everyone can enjoy.
Impressive but simple – Looks beautiful on the table and tastes even better.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

For the green beans:
2 pounds green beans, trimmed
Kosher salt

For the crispy onion topping:
1 tablespoon olive oil, plus more for greasing
1 onion, thinly sliced
½ cup almond flour or gluten-free breadcrumbs
¼ cup freshly grated Parmesan cheese (or nutritional yeast + ½ tablespoon lemon juice for dairy-free)
2 tablespoons chopped fresh parsley, plus more for garnish
½ teaspoon kosher salt, plus more to taste

For the creamy mushroom sauce:
2 tablespoons olive oil
8 ounces baby bella (cremini) mushrooms, thinly sliced
4 cloves garlic, minced or grated
1 teaspoon fresh thyme leaves
3 tablespoons 1:1 gluten-free flour or white whole wheat flour
1¾ cups dairy milk, almond milk, or cashew milk
1 teaspoon kosher salt, plus more to taste
½ teaspoon black pepper
1/8 teaspoon ground nutmeg
7 ounces Greek yogurt or non-dairy yogurt (about ¾ cup)
Flaky sea salt, for garnish (optional)

Directions

Preheat oven to 375°F. Grease a 9×13-inch baking dish with olive oil.
Blanch the green beans: Boil a large pot of salted water. Cook green beans for 4–5 minutes until just tender. Transfer immediately to an ice bath to stop cooking. Drain and pat dry with a kitchen towel.
Prepare the crispy onion topping:
- In a skillet, heat 1 tablespoon olive oil over medium-high heat. Add onions and a pinch of salt. Cook for 7–8 minutes until soft and lightly browned.
- Reduce heat to medium-low. In the same skillet, toast almond flour for 2–3 minutes until golden.
- Combine onions and toasted almond flour in a bowl. Add Parmesan (or nutritional yeast + lemon), parsley, and salt. Toss and set aside.
Make the mushroom sauce:
- In the same skillet, heat 2 tablespoons olive oil over medium heat. Add mushrooms and cook 5–6 minutes until tender.
- Add garlic, thyme, and a pinch of salt. Cook 1 more minute.
- Sprinkle in flour and stir well. Slowly whisk in milk until smooth.
- Season with salt, pepper, and nutmeg. Simmer for 2–3 minutes to thicken.
- Remove from heat and stir in yogurt until fully combined.
Assemble the casserole:
- Add the cooled green beans to the mushroom sauce and toss until coated.
- Pour into the prepared baking dish and top evenly with the crispy onion topping.
Bake:
- Bake uncovered for 25–30 minutes until bubbling and golden brown on top.
- Garnish with extra parsley and flaky sea salt if desired.

Servings and timing

Servings: 8
Prep Time: 15 minutes
Cook Time: 55 minutes
Total Time: 1 hour 10 minutes

Variations

Vegan version: Use non-dairy yogurt, plant-based milk, and nutritional yeast in place of Parmesan.
Nut-free topping: Use gluten-free breadcrumbs instead of almond flour.
Cheesier option: Add more Parmesan or shredded Gruyère to the mushroom sauce.
Add a protein boost: Stir in white beans or cooked quinoa to make it a full meal.
Different mushrooms: Use shiitake or mixed mushrooms for added depth.
Use leeks instead of onions: For a milder, slightly sweet onion flavor.
Add umami: Stir a bit of miso paste or soy sauce into the sauce.
Swap yogurt for sour cream: For a tangier flavor if not avoiding dairy.
Top with crushed crackers: For a crunchier topping alternative.
Make it spicy: Add a pinch of cayenne or red pepper flakes to the sauce.

Storage/Reheating

Storage:
Store leftovers in an airtight container in the refrigerator for up to 4 days.

Reheating:
Reheat in a 350°F oven until warmed through (about 15–20 minutes). Individual portions can be microwaved.

Make ahead:
Prepare the green beans, sauce, and topping separately up to 2 days in advance. Assemble just before baking.

Freezing:
Not recommended, as the yogurt-based sauce may separate upon thawing and reheating.

FAQs

Can I make this casserole fully dairy-free?

Yes. Use non-dairy milk, plant-based yogurt, and nutritional yeast in place of cheese for a fully dairy-free version.

Can I use canned green beans?

Fresh is best for texture, but if using canned, drain and rinse well. Skip blanching and reduce bake time slightly.

Can I use regular flour?

Yes, white whole wheat or all-purpose flour works if gluten-free is not needed.

What can I use instead of almond flour for the topping?

Gluten-free breadcrumbs or crushed gluten-free crackers make a great substitute.

Is this casserole freezer-friendly?

It’s best enjoyed fresh. Freezing may affect the texture of the sauce and topping.

Can I make it ahead of time?

Yes. Assemble the dish up to 24 hours in advance, cover, and refrigerate. Bake just before serving.

How do I make it extra crispy on top?

Broil for 1–2 minutes at the end of baking, watching closely to avoid burning.

What non-dairy milk works best?

Unsweetened almond or cashew milk works well for a creamy, neutral flavor.

Can I double the recipe?

Yes. Use a larger baking dish and extend the baking time by 5–10 minutes if needed.

How can I make it more filling?

Add cooked rice, lentils, or beans to the green bean mixture for a heartier side or main.

Conclusion

Healthy Green Bean Casserole is the perfect balance of comfort and nourishment. With tender green beans, a rich and creamy mushroom sauce, and a crunchy homemade topping, this dish delivers big flavor without compromising on clean ingredients. Whether you’re serving it for a holiday meal or a weeknight dinner, it’s a lighter, better-for-you version of a beloved classic.