This easy green bean casserole is creamy, savory, and topped with crispy golden fried onions. Tender green beans are coated in a rich mushroom sauce and baked until bubbly, making this classic side dish perfect for Thanksgiving, Christmas, holiday dinners, and family gatherings.
It’s simple to prepare, uses everyday ingredients, and can be made ahead of time. The creamy green beans and crunchy onion topping create the perfect combination of textures in every bite.
Why You’ll Love This Green Bean Casserole
- Easy holiday side dish
- Creamy and savory
- Crispy onion topping
- Perfect for Thanksgiving
- Great for Christmas dinner
- Simple ingredients
- Easy to make ahead
- Family-friendly
- Excellent with turkey
- Ready in about 40 minutes
Ingredients
For the Casserole
- 1 1/2 pounds fresh green beans, trimmed
- 2 tablespoons unsalted butter
- 8 ounces mushrooms, sliced
- 1 small yellow onion, diced
- 3 cloves garlic, minced
- 3 tablespoons all-purpose flour
- 1 1/2 cups chicken or vegetable broth
- 1 cup whole milk
- 1/2 cup heavy cream
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/2 teaspoon dried thyme
For the Topping
- 1 1/2 cups crispy fried onions
- 1/4 cup shredded Parmesan, optional
- Fresh parsley, optional
How to Make Easy Green Bean Casserole
1. Preheat the Oven
Preheat the oven to 375°F.
Lightly grease a 9×13-inch baking dish.
2. Blanch the Green Beans
Bring a large pot of salted water to a boil.
Add the trimmed green beans and cook for approximately 3–4 minutes.
They should become bright green and slightly tender while retaining some crispness.
3. Cool the Beans
Drain the green beans and immediately transfer them to a bowl of ice water.
This stops the cooking process and helps preserve their bright green color.
Drain thoroughly.
4. Sauté the Mushrooms
Melt butter in a large skillet over medium heat.
Add sliced mushrooms and diced onion.
Cook for approximately 5–7 minutes, stirring occasionally, until the mushrooms release their moisture and begin to brown.
5. Add Garlic
Add minced garlic.
Cook for approximately 30 seconds until fragrant.
6. Make the Sauce
Sprinkle flour over the mushroom mixture.
Stir continuously for about 1 minute.
7. Add Broth
Slowly pour in the broth while whisking.
Continue stirring until the sauce begins to thicken.
8. Add Milk and Cream
Pour in the milk and heavy cream.
Add Worcestershire sauce, thyme, salt, and black pepper.
Simmer gently for approximately 3–5 minutes until creamy.
9. Combine the Green Beans
Add the blanched green beans to the creamy mushroom sauce.
Stir gently until everything is evenly coated.
10. Transfer to Baking Dish
Pour the green bean mixture into the prepared baking dish.
Spread it into an even layer.
11. Add the First Onion Layer
Sprinkle approximately half of the crispy fried onions over the casserole.
12. Bake
Bake uncovered for approximately 20 minutes, until hot and bubbling around the edges.
13. Add More Crispy Onions
Remove the casserole from the oven.
Sprinkle the remaining fried onions evenly over the top.
14. Finish Baking
Return the casserole to the oven for another 5–8 minutes.
Bake until the onions are golden and crisp.
15. Garnish
Remove from the oven and allow it to rest for a few minutes.
Sprinkle with fresh parsley if desired.
16. Serve
Serve warm alongside turkey, ham, roast chicken, mashed potatoes, and other holiday favorites.
Can I Use Canned Green Beans?
Absolutely.
Canned green beans make this recipe faster.
Drain and rinse them thoroughly before adding them to the mushroom sauce.
Because canned beans are already cooked, you don’t need to blanch them.
Can I Use Frozen Green Beans?
Yes.
Thaw and drain frozen green beans before adding them to the casserole.
They may be slightly softer than fresh green beans.
Are Fresh Green Beans Better?
Fresh green beans provide the best texture and bright color.
They stay slightly crisp after baking instead of becoming overly soft.
Can I Use Canned Cream of Mushroom Soup?
Yes.
For an even easier shortcut, replace the homemade mushroom sauce with approximately two 10.5-ounce cans of condensed cream of mushroom soup mixed with milk.
However, the homemade sauce provides a fresher flavor.
Can I Make This Without Mushrooms?
Yes.
Simply omit the mushrooms and make a creamy onion and garlic sauce instead.
Can I Use Cream of Chicken Soup?
Yes.
Cream of chicken soup works if you don’t need the casserole to be vegetarian.
Can I Make This Vegetarian?
Absolutely.
Use vegetable broth instead of chicken broth and check that your Worcestershire sauce is vegetarian.
Can I Make This Gluten-Free?
Yes.
Replace all-purpose flour with a gluten-free flour blend or another suitable thickener.
Make sure the crispy fried onions and broth are also gluten-free.
Can I Make This Dairy-Free?
Yes.
Use dairy-free butter and unsweetened dairy-free milk.
Choose a suitable dairy-free cream alternative.
Can I Make It Ahead of Time?
Absolutely.
Prepare the casserole without the final crispy onion topping.
Cover and refrigerate.
Add the crispy onions shortly before baking so they remain crunchy.
How Far Ahead Can I Make Green Bean Casserole?
You can prepare it approximately 1 day ahead.
Keep it covered and refrigerated.
Allow it to sit out briefly while the oven preheats, then bake until hot.
Can I Freeze Green Bean Casserole?
Yes, although the texture of the green beans and creamy sauce may change slightly.
For best results, freeze the casserole before baking and add fresh crispy onions after thawing.
How Do I Reheat Green Bean Casserole?
Reheat in a 350°F oven until hot and bubbling.
Add fresh crispy onions toward the end of reheating for the best texture.
How Do I Keep the Fried Onions Crispy?
Don’t add all of the fried onions before baking.
Reserve some for the final 5–8 minutes.
This keeps the topping crunchy and golden.
Can I Add Cheese?
Absolutely.
Try:
- Parmesan
- Cheddar
- Gruyère
- Monterey Jack
- Mozzarella
A small amount of Parmesan adds savory flavor without overpowering the green beans.
Can I Add Bacon?
Yes.
Crispy chopped bacon is an excellent addition.
Stir some into the casserole or sprinkle it over the top.
Can I Add Cheese and Bacon?
Absolutely.
Cheddar, crispy bacon, and green beans create a rich holiday variation.
Can I Add Garlic?
Yes.
Fresh garlic adds excellent flavor to the mushroom sauce.
Can I Add Caramelized Onions?
Absolutely.
Caramelized onions add sweetness and deeper flavor.
Can I Make It Spicy?
Yes.
Add:
- Red pepper flakes
- Cayenne pepper
- Black pepper
- Hot sauce
- Pepper Jack cheese
Can I Use Homemade Fried Onions?
Yes.
Thinly sliced onions can be coated and fried or baked until crispy.
What Mushrooms Are Best?
White button mushrooms and cremini mushrooms work particularly well.
You can also use:
- Baby bella
- Shiitake
- Portobello
- Mixed mushrooms
How Do I Prevent Watery Green Bean Casserole?
Drain the green beans thoroughly after blanching.
Also allow the mushroom sauce to thicken before combining everything.
Excess moisture is one of the most common reasons casseroles become watery.
Why Is My Sauce Too Thick?
Add a small splash of milk or broth and stir until you reach the desired consistency.
Why Is My Sauce Too Thin?
Simmer it a little longer before adding the green beans.
You can also add a small amount of additional flour mixed with butter.
Easy Green Bean Casserole Variations
Classic Thanksgiving Green Bean Casserole
Use fresh green beans, creamy mushroom sauce, and crispy fried onions.
Bacon Green Bean Casserole
Add crispy bacon to the mushroom mixture.
Cheesy Green Bean Casserole
Add sharp cheddar or Parmesan.
Garlic Parmesan Green Bean Casserole
Add extra garlic and Parmesan cheese.
Mushroom Green Bean Casserole
Use a combination of cremini and button mushrooms.
Spicy Green Bean Casserole
Add red pepper flakes and Pepper Jack cheese.
Slow Cooker Green Bean Casserole
Prepare the creamy green bean mixture in a slow cooker and add crispy onions near the end.
Gluten-Free Green Bean Casserole
Use gluten-free flour and gluten-free crispy onions.
What Goes With Green Bean Casserole?
It’s especially delicious with:
- Roast turkey
- Honey glazed ham
- Roast chicken
- Mashed potatoes
- Turkey gravy
- Stuffing
- Cranberry sauce
- Dinner rolls
- Sweet potato casserole
Frequently Asked Questions
Can I use canned green beans?
Yes. Drain and rinse them thoroughly.
Can I use frozen green beans?
Yes. Thaw and drain before using.
Can I use cream of mushroom soup?
Absolutely. It’s a convenient shortcut.
Can I make this without mushrooms?
Yes. Use a creamy garlic and onion sauce instead.
Can I make this ahead?
Yes. Assemble it up to one day ahead and add crispy onions before baking.
Can I freeze it?
Yes, although the texture may change slightly.
How do I keep the onions crispy?
Reserve some onions for the final few minutes of baking.
Can I add bacon?
Absolutely.
Can I add cheese?
Yes. Cheddar, Parmesan, and Gruyère all work well.
Is this vegetarian?
It can be. Use vegetable broth and vegetarian Worcestershire sauce.
How long does it last?
Store leftovers refrigerated for approximately 3–4 days.
Recipe Card
Easy Green Bean Casserole
Prep Time: 15 minutes
Cook Time: 25 minutes
Total Time: 40 minutes
Servings: 8
Course: Side Dish
Cuisine: American
Ingredients
- 1 1/2 pounds fresh green beans
- 2 tablespoons butter
- 8 ounces mushrooms
- 1 small onion
- 3 garlic cloves
- 3 tablespoons flour
- 1 1/2 cups chicken or vegetable broth
- 1 cup whole milk
- 1/2 cup heavy cream
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/2 teaspoon thyme
- 1 1/2 cups crispy fried onions
Instructions
- Preheat oven to 375°F.
- Grease a 9×13-inch baking dish.
- Blanch green beans for 3–4 minutes.
- Transfer to ice water and drain thoroughly.
- Sauté mushrooms and onion in butter for 5–7 minutes.
- Add garlic and cook for 30 seconds.
- Stir in flour.
- Slowly add broth.
- Add milk and cream.
- Add Worcestershire sauce and seasonings.
- Simmer until creamy.
- Stir in green beans.
- Transfer mixture to the baking dish.
- Add half the crispy onions.
- Bake for 20 minutes.
- Add remaining crispy onions.
- Bake another 5–8 minutes until golden.
- Rest briefly.
- Garnish with parsley.
- Serve warm.