If you’re craving a comforting, timeless side dish that never fails to impress, this Classic Green Bean Casserole with Mushroom Sauce and Crispy Onions Recipe is exactly what you need. Combining tender green beans with a rich, creamy mushroom sauce and topped with irresistibly crunchy fried onions, this casserole offers the perfect balance of flavors and textures. It’s a beloved crowd-pleaser at family dinners and holiday feasts alike, and once you master this recipe, you’ll want to make it your go-to dish every time green beans are in season.
Ingredients You’ll Need
This recipe calls for simple, everyday ingredients that pack so much flavor and texture into each bite. Each component plays an essential role, from the fresh green beans providing a vibrant crunch, to the mushroom sauce delivering deep, savory richness, and those crispy onions adding the perfect golden finish.
- Fresh green beans (2 pounds): Choose crisp, bright beans for the best texture and color in your casserole.
- Unsalted butter (2 tablespoons): Adds a luscious base for sautéing vegetables and creating the sauce.
- Yellow onion (1 medium, finely chopped): Brings a gentle sweetness and depth.
- Garlic (3 cloves, minced): Offers a subtle savory punch to brighten the mushroom flavor.
- Button or cremini mushrooms (8 ounces, sliced): The heart of the sauce, juicy and earthy.
- All-purpose flour (¼ cup): Thickens the mushroom sauce perfectly without clumping.
- Half & half (2 cups): Makes the sauce creamy and comforting without being too heavy.
- Chicken or vegetable broth (1 cup): Adds depth and balances the creaminess with savory notes.
- Soy sauce (1 teaspoon): Enhances umami and adds a subtle touch of saltiness.
- Salt (½ teaspoon): Essential for bringing all the flavors together.
- Black pepper (½ teaspoon): Adds a little warmth and spice without overpowering.
- Ground nutmeg (¼ teaspoon): A secret ingredient that adds a hint of warmth and complexity.
- Crispy fried onions (1½ cups): The iconic crunchy topping that makes this casserole unforgettable.
How to Make Classic Green Bean Casserole with Mushroom Sauce and Crispy Onions Recipe
Step 1: Prepare the Green Beans
Start by preheating your oven to 375°F (190°C) because the final bake is crucial for that bubbly, golden top. Bring a large pot of salted water to a boil and blanch the trimmed green beans just for 2 to 3 minutes until they turn bright green and soften slightly. Immediately plunge them into ice water to stop the cooking and keep them crisp—a simple step to ensure your beans stay perfectly tender, not mushy.
Step 2: Cook the Aromatics and Mushrooms
While your beans cool, melt butter in a large skillet over medium heat. Add finely chopped onions and cook until softened, about 3 to 4 minutes, releasing their sweetness. Stir in minced garlic and sliced mushrooms, letting the mushrooms release their moisture and brown gently for 5 to 7 minutes. This slow-cooked mushroom mixture is the flavor powerhouse of this casserole, so don’t rush the caramelization!
Step 3: Create the Creamy Mushroom Sauce
Sprinkle the all-purpose flour evenly over the mushroom mixture and cook it for 1 to 2 minutes to remove any raw flour taste. Gradually whisk in your broth and half & half, stirring constantly to prevent lumps. Season with soy sauce, salt, pepper, and that little pinch of ground nutmeg. Let everything simmer for about 5 minutes until the sauce thickens to a luxuriously creamy consistency that hugs every green bean.
Step 4: Assemble and Bake
In a 9×13-inch casserole dish, combine your blanched green beans, rich mushroom sauce, and half a cup of crispy fried onions. Mix gently right in the dish to coat the beans evenly—this ensures every bite is packed with flavor. Spread the mixture into an even layer and sprinkle the remaining crispy fried onions generously on top. Bake for 20 to 25 minutes until the sauce bubbles up and the onions turn a gorgeous golden brown, promising the perfect crunch.
How to Serve Classic Green Bean Casserole with Mushroom Sauce and Crispy Onions Recipe
Garnishes
For an extra-special touch, sprinkle fresh chopped parsley or chives over the top right after baking. Not only does it add a pop of bright green color, it also adds a fresh herbal note that lightens the creamy richness beautifully.
Side Dishes
This casserole pairs wonderfully with roasted meats like turkey or chicken, making it a must-have for holidays. It also complements hearty mashed potatoes or a simple garlic butter roasted potato, rounding out your meal with comfort and flair.
Creative Ways to Present
For a fun twist, try serving individual portions in ramekins topped with extra crispy onions and a sprinkle of Parmesan cheese. Or turn this dish into a layered green bean bake with alternating layers of mushroom sauce and green beans for a stunning presentation at your next dinner party.
Make Ahead and Storage
Storing Leftovers
After enjoying this casserole, store any leftovers in an airtight container in the refrigerator. It will stay fresh and delicious for up to 3 days, giving you plenty of chances to savor those flavors again.
Freezing
You can freeze this casserole, but keep in mind the crispy onions on top will lose their crunch. To freeze, assemble the casserole without the onions, wrap tightly, and store for up to 2 months. When ready to bake, thaw overnight and add fresh crispy onions before baking.
Reheating
Reheat leftovers gently in the oven at 325°F (160°C) until warmed through, about 15-20 minutes. To refresh the crispy topping, sprinkle a little extra fried onions on top right before warming.
FAQs
Can I use canned green beans instead of fresh?
While fresh green beans give you the best texture and color, you can use canned if needed. Just drain and pat them dry before mixing, but be aware the texture will be softer and less vibrant.
Is there a vegetarian version of this recipe?
Absolutely! Simply use vegetable broth instead of chicken broth, and the mushroom sauce will remain rich and flavorful without any animal products.
Can I make the mushroom sauce ahead of time?
Yes, you can prepare the mushroom sauce a day ahead and refrigerate it. Just warm it gently before assembling the casserole to ensure it mixes well with the green beans.
What’s the best way to get crispy onions for topping?
Crispy fried onions from the store work perfectly, but if you want to make your own, thinly slice onions, toss them in flour, and fry in hot oil until golden brown and crisp. Drain well before using.
Can I substitute half & half with milk or cream?
Half & half is ideal for a creamy but not too heavy sauce, but you can use whole milk for a lighter version or heavy cream for an ultra-rich casserole. Adjust the thickness by reducing broth slightly if you use cream.
Final Thoughts
This Classic Green Bean Casserole with Mushroom Sauce and Crispy Onions Recipe is more than just a side dish – it’s a nostalgic treat that brings warmth and joy to any table. Whether it’s a holiday celebration or a cozy weekday dinner, this casserole promises to delight every bite. Give it a try and watch it become a beloved staple in your recipe collection!
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Classic Green Bean Casserole with Mushroom Sauce and Crispy Onions Recipe
- Prep Time: 20 minutes
- Cook Time: 40 minutes
- Total Time: 1 hour
- Yield: 8 servings
- Category: Casserole
- Method: Baking
- Cuisine: American
- Diet: Halal
Description
A classic and comforting Green Bean Casserole made with fresh green beans, sautéed mushrooms and onions in a creamy sauce, topped with crispy fried onions and baked to golden perfection. This dish is perfect for family dinners and holiday gatherings.
Ingredients
Vegetables and Aromatics
- 2 pounds fresh green beans, trimmed and cut into 2-inch pieces
- 1 medium yellow onion, finely chopped
- 3 cloves garlic, minced
- 8 ounces button or cremini mushrooms, sliced
Dairy and Liquids
- 2 tablespoons unsalted butter
- 2 cups half & half
- 1 cup chicken or vegetable broth
Seasonings and Others
- ¼ cup all-purpose flour
- 1 teaspoon soy sauce
- ½ teaspoon salt
- ½ teaspoon black pepper
- ¼ teaspoon ground nutmeg
- 1½ cups crispy fried onions
Instructions
- Preheat oven: Preheat your oven to 375°F (190°C) to ensure it reaches the right temperature for baking the casserole.
- Blanch green beans: Bring a large pot of salted water to a boil. Add the green beans and cook for 2-3 minutes until bright green and slightly tender. Transfer immediately to a bowl of ice water to stop cooking. Drain and set aside.
- Sauté aromatics and mushrooms: In a large skillet over medium heat, melt butter. Add the finely chopped onion and cook for 3-4 minutes until softened. Stir in the minced garlic and sliced mushrooms, cooking 5-7 minutes until the mushrooms release moisture and start to brown.
- Add flour: Sprinkle the flour over the mushroom mixture and stir to coat evenly. Cook for 1-2 minutes to remove the raw flour taste and create a roux base for the sauce.
- Make the sauce: Gradually whisk in the chicken or vegetable broth and half & half, stirring constantly to avoid lumps. Add soy sauce, salt, pepper, and ground nutmeg. Simmer for about 5 minutes, stirring often, until the sauce thickens to a creamy consistency.
- Combine casserole ingredients: In a 9×13-inch casserole dish, add the blanched green beans, the mushroom sauce, and half a cup of crispy fried onions. Mix everything together directly in the dish until the green beans are evenly coated. Spread in an even layer.
- Top with crispy onions: Sprinkle the remaining crispy fried onions evenly over the top of the green bean mixture for a crunchy topping.
- Bake: Bake in the preheated oven for 20-25 minutes until the sauce is bubbling and the onions on top are golden brown. Let cool for a few minutes before serving.
Notes
- Using fresh green beans is key for the best texture and flavor, but frozen can be used if fresh aren’t available; just adjust blanching time accordingly.
- Half & half creates a creamy sauce without being overly heavy, but you can substitute with whole milk or cream for different richness.
- Be sure to whisk the sauce constantly when adding liquids to prevent lumps in the casserole sauce.
- For a vegetarian version, use vegetable broth instead of chicken broth and ensure the crispy fried onions are free from animal products.
- This casserole can be assembled a day ahead; cover and refrigerate, then bake when ready to serve.
