Rachel’s Homemade Green Bean Casserole

This homemade green bean casserole is creamy, comforting, and made completely from scratch with fresh vegetables and a rich mushroom sauce. Topped with crisp onion rings, it delivers all the classic holiday flavors in a lighter, gluten-free–friendly way that still feels indulgent and festive.

Why You’ll Love This Recipe

This green bean casserole is worlds apart from the canned-soup version. Fresh green beans stay tender-crisp instead of mushy, and the mushroom sauce is deeply savory without relying on processed ingredients. Coconut cream adds luxurious richness while keeping the dish dairy-light, and the crisp onion rings on top give you that irresistible crunch in every bite.

It’s an excellent option for guests who avoid gluten, since the sauce and coating are thickened with gluten-free flour or arrowroot. You can also easily adapt it to be fully dairy-free by swapping the ghee for a plant-based fat. Whether it’s a holiday table centerpiece or a special family side dish, this casserole feels homemade, wholesome, and satisfying.

Ingredients

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

For the green beans

• 1 1/2 pounds (about 680 g) fresh green beans, trimmed and cut into bite-sized pieces

For the mushroom sauce

• 2 tablespoons clarified butter or ghee
• 2 cups button mushrooms, sliced
• 1 large yellow onion, diced (about 1 1/2 cups)
• 2 fresh garlic cloves, minced
• 1 tablespoon coconut aminos
• 1/2 cup coconut cream (use the thick cream, not coconut milk)
• 1 cup vegetable broth or chicken broth
• 1 tablespoon gluten-free flour or arrowroot powder
• 1/4 teaspoon fine sea salt, plus more to taste
• 1/4 teaspoon ground black pepper, plus more to taste

For the crispy onions

• 1 large yellow onion, sliced into thin rings
• 2 large eggs
• 4 tablespoons gluten-free flour
• 2 tablespoons avocado oil or olive oil
• Pinch of sea salt and black pepper, for seasoning the batter

Optional garnish

• Curly parsley, chopped
• Ground black pepper, to taste
• Sea salt flakes, to taste

Directions

1. Preheat the oven
   • Preheat your oven to 375°F (190°C).
   • Lightly grease a large casserole dish with a thin layer of avocado oil or olive oil and set aside.
2. Prepare the crispy onion topping
   • In a small bowl, whisk the eggs and gluten-free flour together until the mixture is smooth and lump-free.
   • Season the batter with a small pinch of sea salt and black pepper.
   • Heat a large skillet over medium-low heat and add 1 tablespoon of the oil.
   • Dip the onion rings into the batter, letting any excess drip off.
   • Arrange the coated onion rings in the hot skillet in a single layer and cook for 2–3 minutes per side, until golden brown and crisp.
   • Transfer cooked onion rings to a plate lined with a clean kitchen towel or paper towel.
   • Add the remaining 1 tablespoon oil to the skillet and repeat with the rest of the onion rings, working in small batches so they stay crisp.
3. Blanch the green beans
   • Bring a large pot of water to a rolling boil.
   • Fill a large bowl with ice water and keep it nearby.
   • Add the trimmed green beans to the boiling water and cook for 3–4 minutes, until they are bright green and just tender-crisp.
   • Using tongs or a slotted spoon, quickly transfer the green beans to the ice water bath.
   • Let them sit in the ice water for 1–2 minutes to stop the cooking, then drain very well and set aside.
4. Make the mushroom sauce
   • In a large skillet, melt the ghee over medium heat.
   • Add the sliced mushrooms, diced onion, and minced garlic.
   • Sauté for 4–5 minutes, stirring often, until the mushrooms release their moisture and the onions soften and begin to turn translucent.
   • In a separate bowl, whisk together the coconut cream, coconut aminos, broth, and gluten-free flour or arrowroot until completely smooth and no lumps remain.
   • Pour this coconut cream mixture into the skillet over the mushroom mixture.
   • Cook, stirring constantly, for 3–5 minutes, until the sauce thickens to a creamy consistency that coats the back of a spoon.
   • Season with 1/4 teaspoon sea salt and 1/4 teaspoon black pepper, adjusting to taste.
   • Remove from the heat.
5. Assemble the casserole
   • Place the blanched green beans into the prepared casserole dish and spread them into an even layer.
   • Pour the hot mushroom sauce over the green beans.
   • Gently toss or fold with a spatula so the beans are evenly coated in the sauce, then smooth the top.
6. Add the crispy onions and bake
   • Arrange the crispy onion rings evenly over the top of the green bean mixture.
   • Loosely cover the dish with parchment paper or foil to prevent over-browning.
   • Bake in the preheated oven for about 20 minutes, or until the casserole is bubbling around the edges and lightly golden.
7. Finish and serve
   • Remove the casserole from the oven and let it stand for about 5–10 minutes to set slightly.
   • Garnish with chopped curly parsley, a pinch of sea salt flakes, and freshly ground black pepper if desired.
   • Serve warm.

Servings and timing

• Servings: About 6 servings
• Prep time: 25–30 minutes
• Cook time: 25–30 minutes
• Total time: 50–60 minutes

This timing includes preparing the onion rings, blanching the green beans, making the mushroom sauce, assembling the casserole, and baking until bubbly.

Variations

• Dairy-free version
  Replace the ghee with avocado oil or olive oil in the mushroom sauce to make the base fully dairy-free while keeping the same rich texture.
• Extra-creamy casserole
  Add an additional 1/4 cup coconut cream to the sauce for a thicker, richer consistency. If it becomes too thick, thin with a splash more broth.
• Herb-infused flavor
  Stir 1–2 teaspoons of finely chopped fresh thyme or rosemary into the mushroom sauce for a deeper, more aromatic profile.
• Spicy twist
  Add a small pinch of red pepper flakes or a dash of your favorite hot sauce to the mushroom sauce for a gentle heat that balances the creaminess.
• Different mushroom types
  Swap some or all of the button mushrooms for cremini or shiitake mushrooms to intensify the earthy, savory flavor.
• Crunchy topping blend
  Mix some extra gluten-free flour–dusted onion pieces into the topping or add a small handful of crushed gluten-free crackers along with the crispy onions for more texture.

Storage/Reheating

• Refrigeration
  Allow the casserole to cool to room temperature. Cover the dish tightly with foil or transfer leftovers to an airtight container. Store in the refrigerator for up to 3 days.
• Freezing
  For best texture, it’s ideal to freeze before baking and without the crispy onion topping. Assemble the green beans and mushroom sauce in the dish, cool completely, wrap well, and freeze for up to 1 month. Add freshly made crispy onions and bake from thawed.
• Reheating in the oven
  Preheat the oven to 350°F (175°C). Cover the casserole with foil and heat for 15–20 minutes, or until hot throughout. Remove the foil for the last 5 minutes to help the topping re-crisp.
• Reheating in the microwave
  Place a portion on a microwave-safe plate and heat on medium power in 30–45 second intervals, stirring gently as needed, until warmed through. The topping will be softer than when reheated in the oven.
• Refreshing the topping
  If the onion topping loses its crunch, you can place the casserole under the broiler for 1–2 minutes, watching closely, until it crisps up again.

FAQs

Can I use frozen green beans instead of fresh?

Yes, you can use frozen green beans if fresh are unavailable. Thaw them first, pat dry to remove excess moisture, and skip the blanching step or shorten it slightly since they are partially cooked.

Do I have to blanch the green beans?

Blanching helps the beans keep their bright color and tender-crisp texture after baking. Skipping this step can result in beans that are either too firm or overcooked, so blanching is strongly recommended.

Can I make this casserole ahead of time?

You can assemble the green beans and mushroom sauce up to a day in advance, cover, and refrigerate. Prepare the crispy onions closer to serving time and add them just before baking to keep the topping crunchy.

How can I make the mushroom sauce thicker?

If the sauce is too thin, simmer it for a few extra minutes while stirring, or whisk an additional teaspoon of gluten-free flour or arrowroot into a small amount of broth, then stir that mixture into the sauce and cook until it thickens.

What can I use instead of coconut cream?

If you do not want to use coconut cream, you can substitute an equal amount of a thick dairy-free cream alternative or a rich, unsweetened plant-based cooking cream. Choose one that is neutral in flavor and suitable for savory recipes.

Can I reduce the sodium in this recipe?

Yes. Use low-sodium broth, season lightly with sea salt at first, and then adjust only after tasting the finished sauce. You can also skip the final sprinkle of salt flakes on top.

Is this recipe gluten-free?

The recipe can be fully gluten-free when you use gluten-free flour or arrowroot powder in both the sauce and onion batter, and ensure your broth and coconut aminos are certified gluten-free.

How do I keep the onion rings crispy?

Fry the onion rings in small batches so they do not steam, drain them on a towel-lined plate, and add them to the casserole just before baking. Loosely covering the dish while baking also helps prevent them from softening too much.

Can I use a different type of onion?

Yes. While yellow onions are classic for both the sauce and topping, you can use white onions or sweet onions. Sweet onions will give a milder, sweeter flavor, especially in the crispy topping.

What size casserole dish should I use?

A medium to large casserole dish, around 9×13 inches (23×33 cm) or similar capacity, works well for this amount of green beans and sauce. The casserole should be filled but not overflowing, with a bit of room for bubbling as it bakes.

Conclusion

Rachel’s homemade green bean casserole transforms a traditional holiday side into a fresh, from-scratch dish with vibrant vegetables, a velvety mushroom sauce, and a golden, crispy onion topping. It is flexible enough to suit gluten-free and dairy-light diets while still delivering all the comfort and richness you expect from a festive casserole. Serve it alongside your favorite main dishes, and it will quickly become a requested favorite for special gatherings and cozy family dinners alike.

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