Old-School Green Bean Casserole

Featured in: One-Pan Comforts

This nostalgic dish combines tender green beans with a creamy sauce made from mushrooms, butter, cream, and broth. After simmering, it’s topped with crispy fried onions and baked until golden and bubbling. Perfect as a comforting side for holidays and family dinners, it’s easy to prepare in under an hour and can be made ahead. Variations include adding sharp cheddar for extra richness, enhancing the traditional flavors with a satisfying crunch.

Updated on Sat, 15 Nov 2025 12:47:00 GMT
Golden, bubbly Old-School Green Bean Casserole with a creamy mushroom sauce and crispy onions. Save
Golden, bubbly Old-School Green Bean Casserole with a creamy mushroom sauce and crispy onions. | coraloven.com

A nostalgic creamy side dish featuring tender green beans savory mushrooms and crispy fried onions—a classic for holiday feasts and family dinners.

This casserole always reminds me of potluck dinners at my grandparents' house. Everyone went back for seconds and the crispy fried onions were everyone's favorite part!

Ingredients

  • Fresh green beans: 900 g (2 lb) trimmed and cut into 5 cm (2-inch) pieces or substitute with 900 g frozen cut green beans thawed and drained
  • Unsalted butter: 2 tbsp
  • Cremini or button mushrooms: 250 g (9 oz) sliced
  • Small yellow onion: 1 finely chopped
  • Garlic cloves: 2 minced
  • All-purpose flour: 2 tbsp
  • Whole milk: 240 ml (1 cup)
  • Heavy cream: 120 ml (½ cup)
  • Low-sodium vegetable broth: 120 ml (½ cup)
  • Salt: 1 tsp
  • Black pepper: ½ tsp
  • Ground nutmeg (optional): ½ tsp
  • Crispy fried onions: 150 g (1½ cups) store-bought or homemade

Instructions

Preheat oven:
Set oven to 180°C (350°F).
Blanch green beans:
Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender and bright green. Drain and rinse under cold water.
Sauté vegetables:
In a large skillet over medium heat melt the butter. Add mushrooms and cook for 5-6 minutes until tender. Add onion and garlic and cook for 2-3 minutes until softened.
Make sauce:
Stir in flour and cook for 1 minute. Gradually whisk in milk cream and broth. Simmer and cook until thickened about 5 minutes. Season with salt pepper and nutmeg (if using).
Combine beans and sauce:
Add drained green beans tossing to coat evenly in the sauce.
Layer and bake:
Transfer mixture to a 2-liter (2-quart) baking dish. Sprinkle half the crispy fried onions on top.
Bake and finish:
Bake for 25 minutes until bubbling. Top with remaining onions and bake for 5-7 minutes more until golden. Cool 5 minutes before serving.
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This dish is a staple at our family holiday table and has made its way into birthday and Sunday dinners too. Passing the casserole around is a small tradition that always gets everyone laughing.

Make Ahead Tips

Assemble up to the baking step and refrigerate for up to 24 hours. Add onions just before baking to keep them crisp.

Allergen Information

Contains milk and wheat and may contain soy depending on your fried onions and broth. Read packages to ensure safety for all guests.

Serving Suggestions

Serve alongside roast turkey or chicken or as part of a vegetarian holiday spread.

A comforting, oven-baked dish of Old-School Green Bean Casserole, perfect for Thanksgiving dinner. Save
A comforting, oven-baked dish of Old-School Green Bean Casserole, perfect for Thanksgiving dinner. | coraloven.com

This creamy casserole always disappears fast—don't forget the extra crispy onions for topping!

Recipe FAQs

How do I ensure the green beans stay tender but crisp?

Boil the green beans for about 5 minutes until just tender, then immediately rinse them under cold water to stop cooking and preserve their bright color and crispness.

Can I use frozen green beans instead of fresh?

Yes, frozen cut green beans can be substituted; just make sure to thaw and drain them thoroughly before cooking.

What can I add for extra flavor in the sauce?

Adding grated sharp cheddar or Gruyère cheese into the sauce base adds richness and depth to the creamy mixture.

How do I achieve crispy fried onions on top?

Use store-bought or homemade crispy fried onions and add half before baking; after initial baking, top with the rest and bake again to get a golden, crunchy topping.

Is it possible to prepare this dish ahead of time?

Yes, assemble the casserole up to the point before adding the onions and baking, then refrigerate for up to 24 hours. Add the onions and bake just before serving.

What dishes pair well with this green bean side?

This creamy green bean combination pairs beautifully with roast turkey, chicken, or hearty main courses at holiday meals.

Old-School Green Bean Casserole

Tender green beans with a creamy mushroom sauce topped with crispy fried onions, perfect for festive meals.

Prep time
15 minutes
Time to cook
35 minutes
Time Required
50 minutes
Created by Hannah Lewis


Skill level Easy

Cuisine American

Makes 6 Portions

Dietary details Meatless

What You Need

Vegetables

01 2 lb fresh green beans, trimmed and cut into 2-inch pieces (or frozen, thawed and drained)

Sauce Base

01 2 tbsp unsalted butter
02 9 oz cremini or button mushrooms, sliced
03 1 small yellow onion, finely chopped
04 2 garlic cloves, minced
05 2 tbsp all-purpose flour
06 1 cup whole milk
07 ½ cup heavy cream
08 ½ cup low-sodium vegetable broth
09 1 tsp salt
10 ½ tsp black pepper
11 ½ tsp ground nutmeg (optional)

Topping

01 1½ cups crispy fried onions (store-bought or homemade)

How To Make

Step 01

Preheat Oven: Set oven temperature to 350°F.

Step 02

Blanch Green Beans: Boil salted water in a large pot. Add green beans and cook for 5 minutes until tender-crisp. Drain and rinse under cold water to stop cooking. Set aside.

Step 03

Sauté Mushrooms and Aromatics: Melt butter in a large skillet over medium heat. Cook mushrooms for 5–6 minutes until browned. Add onion and garlic; sauté 2–3 minutes until softened.

Step 04

Prepare Sauce: Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Simmer until thickened, about 5 minutes. Season with salt, pepper, and nutmeg if using.

Step 05

Combine Beans with Sauce: Add drained green beans to skillet and toss to coat evenly with sauce.

Step 06

Assemble Casserole: Transfer mixture to a 2-quart baking dish. Sprinkle half of the crispy fried onions evenly over the top.

Step 07

Bake Initial Layer: Bake for 25 minutes until bubbling.

Step 08

Add Topping and Finish Baking: Remove from oven, sprinkle remaining onions on top, and bake for an additional 5–7 minutes until golden and crisp.

Step 09

Rest Before Serving: Allow dish to cool for 5 minutes before serving.

Needed utensils

  • Large pot
  • Colander
  • Large skillet
  • Whisk
  • 2-quart baking dish
  • Oven

Allergy details

Check components for allergens, and get advice from a medical expert if you're unsure.
  • Contains milk (dairy), wheat (gluten), and potentially soy (in store-bought fried onions)

Nutrition Details (each serving)

Details are for informational purposes, not medical use.
  • Kilocalories: 265
  • Fat content: 15 g
  • Carbohydrates: 25 g
  • Proteins: 6 g