Old School Green Bean Casserole

Featured in: Crispy & Crunchy Recipes

This comforting side features tender green beans enveloped in a creamy sauce made with sautéed mushrooms, onions, and a hint of garlic. The dish is enriched with a smooth blend of milk, cream, and vegetable broth, thickened with flour, and gently seasoned for balanced flavor. Crispy fried onions provide a rich, golden topping adding texture and aroma. Ideal for holiday feasts or cozy family dinners, it pairs wonderfully with roasted poultry or hearty mains. Simple preparation and baking develop savory warmth and familiar tastes cherished across generations.

Updated on Sat, 15 Nov 2025 10:54:00 GMT
Golden-brown, bubbly Old-School Green Bean Casserole with crispy onions, a comforting classic side dish. Save to Pinterest
Golden-brown, bubbly Old-School Green Bean Casserole with crispy onions, a comforting classic side dish. | chomzo.com

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

I remember the first time I made this casserole from scratch for Thanksgiving. The aroma of mushrooms and onions brought everyone to the kitchen, ready for a taste before dinner even began.

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
  • Yellow onion: 1 small, 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:
Preheat the oven to 180°C (350°F).
Cook green beans:
Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender but still bright green. Drain and immediately rinse under cold water to stop cooking. Set aside.
Prepare sauce base:
In a large skillet over medium heat, melt the butter. Add mushrooms and cook for 5-6 minutes until tender and browned. Add onion and garlic, cooking for another 2-3 minutes until softened.
Thicken sauce:
Stir in the flour and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and broth. Bring to a simmer and cook until thickened, about 5 minutes. Season with salt, pepper, and nutmeg (if using).
Combine with beans:
Add the drained green beans to the skillet and toss to coat evenly in the sauce.
Assemble casserole:
Transfer the mixture to a 2-liter (2-quart) baking dish. Sprinkle half of the crispy fried onions on top.
Bake:
Bake for 25 minutes until bubbling. Remove from oven, top with remaining onions, and bake for 5-7 minutes more until golden and crisp.
Rest and serve:
Let cool for 5 minutes before serving.
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| chomzo.com

This casserole always makes an appearance on our holiday table. My kids love helping sprinkle the onions on top before it goes in the oven.

Required Tools

Large pot, colander, large skillet, whisk, 2-liter (2-quart) baking dish, oven.

Allergen Information

Contains: Milk (dairy), Wheat (gluten in flour and fried onions), Soy (possible in store-bought fried onions). Double-check labels for fried onions and broth for allergens.

Nutritional Information

Per serving: Calories: 265. Total Fat: 15 g. Carbohydrates: 25 g. Protein: 6 g.

Creamy Old-School Green Bean Casserole with tender beans and mushrooms, perfect for a holiday meal. Save to Pinterest
Creamy Old-School Green Bean Casserole with tender beans and mushrooms, perfect for a holiday meal. | chomzo.com

This old-school green bean casserole brings everyone together and is sure to become a tradition at your table.

Common Questions

How can I keep green beans tender but crisp?

Blanch green beans briefly in boiling salted water then rinse in cold water to stop cooking. This locks in color and crispness before combining with sauce.

Can I use frozen green beans instead of fresh?

Yes, thaw and drain frozen cut green beans before using. The texture may be slightly softer but remains delicious when baked.

What gives the sauce its creamy texture?

Butter, milk, heavy cream, and flour create a smooth roux-based sauce enriched with mushrooms and onions for depth and creaminess.

How to make fried onion topping crispy and flavorful?

Use either store-bought or homemade fried onions. Add half before baking and the rest near the end to maintain a golden crisp surface.

Can I prepare this dish in advance?

Yes, assemble up to the baking step and refrigerate for up to 24 hours. Add onions and bake right before serving to preserve freshness.

What dishes pair well with this creamy side?

It complements roasted turkey, chicken, or other hearty mains, adding comfort and nostalgic flavors to the meal.

Old School Green Bean Casserole

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

Prep Duration
15 minutes
Cook Duration
35 minutes
Time Needed
50 minutes
Author Maya Brooks


Skill Level Easy

Cuisine Type American

Makes 6 Portions

Dietary Info Meat-free

Required Ingredients

Vegetables

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

Sauce Base

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

Topping

01 1½ cups crispy fried onions, store-bought or homemade

Preparation Steps

Step 01

Preheat Oven: Preheat the oven to 350°F.

Step 02

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 to stop cooking. Set aside.

Step 03

Cook Mushrooms, Onion, and Garlic: In a large skillet over medium heat, melt butter. Add mushrooms and sauté for 5-6 minutes until tender and browned. Add onion and garlic; cook 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 gently until sauce thickens, about 5 minutes. Season with salt, pepper, and nutmeg if using.

Step 05

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

Step 06

Assemble in Baking Dish: Transfer mixture to a 2-quart baking dish. Sprinkle half the crispy fried onions evenly on top.

Step 07

Bake Initial Layer: Bake for 25 minutes until the mixture is bubbling.

Step 08

Add Final Topping and Bake: Remove from oven, top with remaining fried onions, and bake for an additional 5 to 7 minutes until golden and crisp.

Step 09

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

Tools Needed

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

Allergy Details

Look at the ingredient list to spot allergens. If you have questions, ask a healthcare provider.
  • Contains milk (dairy), wheat (gluten), and possibly soy from commercial fried onions and broth; verify product labels.

Nutrition Details (each portion)

These facts are just for your reference and not substitute for medical guidance.
  • Energy: 265
  • Fats: 15 g
  • Carbohydrates: 25 g
  • Proteins: 6 g