Healthy Green Bean Casserole

This Healthy Green Bean Casserole is made from scratch with fresh green beans, a creamy homemade mushroom sauce, and crispy baked Parmesan onions. The perfect lighter holiday side dish for Thanksgiving, Christmas, or any family dinner!

This Healthy Green Bean Casserole recipe is a lighter and more wholesome take on the classic side dish that is creamy, comforting and SO delicious. Traditional green bean casserole uses canned green beans, canned cream of mushroom soup and fried onions versus this recipe using fresh ingredients. Made with crisp-tender green beans, a homemade mushroom cream sauce and a crispy onion topping that is baked, not fried. Whether serving for Thanksgiving, Christmas, Easter or a cozy weeknight dinner, this healthier take is just as satisfying without the guilt!

Why You’ll Love this Recipe

• Made from scratch – no Campbell’s cream of mushroom canned soup or packaged fried onions needed in this homemade recipe!
• Wholesome ingredients – this casserole is made with fresh green beans, a homemade mushroom sauce and topped with fresh crispy onions.
• Rich and creamy – the savory mushroom sauce is packed with so much flavor and has the perfect light texture that perfectly coats the green beans without feeling too heavy.
• Perfect for holidays – this classic dish is a family favorite! The perfect addition to your Thanksgiving table or whether celebrating Christmas, Easter or simply want a cozy weeknight dinner at home.

Ingredients You’ll Need

• green beans – you’ll need 24 oz of fresh green beans or french green beans (also called haricot verts) in this recipe. No canned green beans here!
• mushrooms – fresh mushrooms add umami richness and a hearty texture to the sauce. You can use baby bella mushrooms (cremini mushrooms) or white button mushrooms.
• flour – I used all-purpose flour to help thicken the creamy sauce and add a light coating to the onions. You could also use gluten-free flour or oat flour.
• half and half – makes the sauce nice and creamy. You can also use full fat coconut milk for a lighter option or even heavy cream if that’s all you have.
• chicken broth – this is used for the base of the mushroom sauce which adds so much flavor. You could also use vegetable broth or chicken stock.
• soy sauce – low-sodium soy sauce adds a rich, savory umami flavor that enhances the homemade mushroom sauce. Feel free to use tamari or coconut aminos if gluten-free.
• butter – needed to sauté the mushrooms and help give them that golden color and flavor.
• garlic – you can use fresh chopped garlic or minced garlic from the jar.
• fresh thyme – adds a fresh herby and aromatic flavor that tastes amazing with the rest of the ingredients.
• seasonings – a combination of onion powder, garlic powder, salt and black pepper.
• onions – you’ll need 2 large yellow onions that will be thinly sliced to make the crispy onion topping. Trust me, they taste so much better than store-bought fried onions! You could also make crispy shallots.
• breadcrumbs – I used whole grain panko breadcrumbs to make the onions crispy, but you could also use gluten-free panko breadcrumbs.
• parmesan cheese – adds flavor and allows us to use less breadcrumbs in the crispy onion topping.

How to Make Green Bean Casserole

1. Make the crispy onion topping. Place the sliced onions in a large bowl and drizzle with olive oil. Toss to make sure the onions are all coated. Add in the flour, breadcrumbs, parmesan cheese, garlic powder and salt, tossing to combine.
2. Bake the onions. Spread the onion mixture out onto a large baking sheet lined with parchment paper and sprayed with nonstick spray. Bake the onions at 450 degrees F for 25 to 30 minutes, tossing halfway through, until crispy and golden brown. Once done cooking, set the onions aside and reduce the heat to 375 degrees F.
3. Blanch the green beans. While the onions are cooking, fill a large pot with water and add a tablespoon of salt. Bring to a boil then add in the fresh green beans. Blanch the green beans for 5-6 minutes, until tender, then drain in a colander. Transfer them to a bowl of ice water (ice bath) for a few minutes to stop the cooking process, then drain well and pay dry with a paper towel.
4. Sauté the mushrooms. In a medium saucepan or large skillet on medium heat, melt butter then add in garlic and diced mushrooms. Sauté the mushrooms for a few minutes until soft, then add in the flour and stir to combine.
5. Make the sauce. Add in the half and half and chicken broth, bringing to a boil. Stir continuously to remove any lumps, then turn the heat down to medium-low and continue cooking for 2 to 3 minutes, until the sauce has thickened up a bit. Mix in the sea salt, pepper, onion powder and fresh thyme leaves and remove from heat.
6. Assemble the casserole. Transfer the green beans to a 9×13 casserole baking dish coated with nonstick spray and pour the mushroom cream sauce evenly over all the green beans. Top with the crispy onions along with any extra crunch breadcrumbs left on the sheet pan.
7. Bake the casserole. Bake the green bean casserole at 375 degrees F for 15 to 20 minutes, until heated through. Serve and enjoy!

Tips for the Best Healthy Green Bean Casserole

• Use fresh green beans – fresh green beans provide better texture, flavor and nutrition than canned. Trim the edges and blanch them just until tender-crisp to avoid a soggy casserole.
• Make sure to blanch the beans – this ensures you have tender yet crisp green beans while still maintaining their beautiful color. This also helps them not to get mushy!
• Slice the onions thin and evenly – uniform slices ensure they cook at the same rate, giving you perfectly crispy onions without burnt edges or undercooked pieces.
• Don’t skip browning the mushrooms – allow the mushrooms to cook until they release their moisture and turn golden. This step builds deep, savory flavor and keeps the sauce from tasting bland.
• Taste the sauce before assembling the casserole – since the sauce is the heart of the recipe, adjust the salt, pepper, or thyme before pouring it over the green beans.
• Let the casserole rest for 5–10 minutes before serving – this gives the sauce time to thicken slightly and makes serving much easier.
• Prep ahead of time – this casserole is the perfect make-ahead dish! Simply assemble everything except the topping, cover tightly, and refrigerate up to 24 hours in advance for a stress-free holiday.

Frequently Asked Questions

Prepping and Storage

• To Store: Store leftovers in a sealed, airtight container in the refrigerator for up to 5 days. This casserole can also easily be prepped up to 24 hours in advance, just add the crispy onion topping right before baking.
• To Freeze: Freeze the assembled casserole without the onion topping in a freezer-safe dish, covered tightly, for up to 2 months. When ready to bake, thaw in the fridge overnight. Perfect for a stress-free holiday!
• To Reheat: Let the casserole thaw out in the fridge overnight. When ready to bake, let it come to room temperature as the oven preheats, then add the crispy onion topping and bake as directed. If you froze individual servings, simply let those thaw out and warm in the microwave until heated through.
• To Make Ahead: Prepare the casserole and mushroom sauce up to one day in advance. Refrigerate, then add the crispy onions just before baking for the best texture.

More Holiday Side Dishes

• Healthy Sweet Potato Casserole
• Sausage, Apple and Herb Stuffing
• Healthy Mashed Potatoes
• Maple Glazed Butternut Squash and Brussels
• Bourbon Maple Pecan Sweet Potatoes
• Healthy Cranberry Sauce
• Honey Butter Dinner Rolls

Hope you all add this Healthy Green Bean Casserole to your Thanksgiving menu! If you love this as much as we do, please leave a ⭐️⭐️⭐️⭐️⭐️ star rating below and don’t forget to tag me on Instagram using the hashtag #eatyourselfskinny!