Old-School Green Bean Casserole

Featured in: Hearty Comfort Food

This comforting dish features tender green beans coated in a creamy mushroom sauce, topped with crunchy fried onions. The green beans are briefly boiled to keep their bright color and crispness, then combined with a savory blend of sautéed mushrooms, onions, and garlic. A rich sauce made from butter, flour, milk, cream, and vegetable broth binds the ingredients together, seasoned delicately with salt, pepper, and nutmeg. The casserole is baked until bubbling and golden, making it a beloved side for festive meals.

Updated on Tue, 11 Nov 2025 13:55:00 GMT
Classic Old-School Green Bean Casserole, bubbling hot, topped with crunchy fried onions and ready to serve. Save
Classic Old-School Green Bean Casserole, bubbling hot, topped with crunchy fried onions and ready to serve. | dashnosh.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 brings me back to childhood family gatherings where the aroma of bubbling sauce and crunchy onions filled our kitchen.

Ingredients

  • Fresh Green Beans: 900 g (2 lb) trimmed and cut into 5 cm (2-inch) pieces (or 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

Prep Oven:
Preheat 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.
Sauté Vegetables:
In a large skillet over medium heat melt butter. Add mushrooms and cook for 5-6 minutes until tender and browned. Add onion and garlic and cook for 2-3 minutes until softened.
Prepare Sauce:
Stir in flour and cook for 1 minute. Gradually add milk cream and broth whisking constantly. Simmer and cook until thickened about 5 minutes. Season with salt pepper and nutmeg.
Combine Beans and Sauce:
Add drained green beans to skillet and toss to coat.
Assemble:
Transfer mixture to a 2-liter baking dish and sprinkle half 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.
Finish:
Let cool for 5 minutes before serving.
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Sharing this dish with family always sparks stories from the past and everyone competes for the last scoop of crispy onion topping.

Serving Suggestions

This casserole pairs perfectly with roast turkey chicken or even vegetarian main courses and brings color to any holiday table.

Make Ahead Tips

Assemble casserole up to baking and refrigerate up to 24 hours. Add onions and bake just before serving for best texture.

Customization Ideas

Add grated cheddar or Gruyère cheese for a richer flavor or toss in cooked bacon for a smoky touch.

Creamy homemade Old-School Green Bean Casserole with tender green beans, mushrooms, and golden toppings. Save
Creamy homemade Old-School Green Bean Casserole with tender green beans, mushrooms, and golden toppings. | dashnosh.com

This green bean casserole is a crowd-pleaser with classic flavors and irresistible textures. Serve hot and watch it disappear fast!

Kitchen Q&A

How do I keep green beans tender but crisp?

Blanch green beans in boiling salted water for about 5 minutes, then rinse under cold water to stop cooking. This preserves their bright color and crunch.

Can I use frozen green beans instead of fresh?

Yes, thaw and drain frozen cut green beans before cooking. They work well in this creamy dish without losing texture.

What mushrooms work best for the sauce?

Cremini or button mushrooms are ideal for their mild yet earthy flavor, enhancing the creamy sauce nicely.

How do I make the sauce thick and creamy?

Sauté mushrooms and aromatics, then incorporate butter, flour, milk, cream, and broth while whisking until thickened over medium heat.

What can I add for extra flavor?

Adding grated sharp cheddar or Gruyère cheese to the sauce creates a richer, more savory depth.

How do I achieve crispy fried onions topping?

Use store-bought crispy fried onions or prepare homemade by frying thinly sliced onions in oil until golden and crisp.

Old-School Green Bean Casserole

Creamy green beans with sautéed mushrooms and crispy fried onions, a comforting holiday side.

Prep Duration
15 min
Cook Duration
35 min
Complete Duration
50 min
Created by Tyler Morgan

Recipe Type Hearty Comfort Food

Skill Level Easy

Cultural Heritage American

Output 6 Portion Size

Nutritional Categories Meat-Free

What You'll Need

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 1/2 cup heavy cream
08 1/2 cup low-sodium vegetable broth
09 1 teaspoon salt
10 1/2 teaspoon black pepper
11 1/2 teaspoon ground nutmeg (optional)

Topping

01 1 1/2 cups crispy fried onions (store-bought or homemade)

Method

Step 01

Preheat oven: Set the oven temperature to 350°F (180°C).

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 immediately under cold water to stop cooking. Set aside.

Step 03

Sauté mushrooms and aromatics: Melt butter in a large skillet over medium heat. Add mushrooms and cook for 5 to 6 minutes until tender and browned. Incorporate onion and garlic, cooking for an additional 2 to 3 minutes until softened.

Step 04

Prepare sauce: Stir in flour and cook for 1 minute while stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Bring the mixture to a simmer and cook until thickened, about 5 minutes. Season with salt, pepper, and nutmeg if using.

Step 05

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

Step 06

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

Step 07

Bake casserole: Bake for 25 minutes until bubbly. Remove from oven, add the remaining fried onions on top, and bake for an additional 5 to 7 minutes until onions are golden and crisp.

Step 08

Rest and serve: Allow to cool for 5 minutes before serving.

Kitchen Tools Needed

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

Allergy Alerts

Review ingredients carefully for potential allergens and seek professional medical guidance if concerned.
  • Contains milk (dairy), wheat (gluten), and potential soy from fried onions.

Nutrition Details (serving size)

Numbers shown are estimates only - consult healthcare providers for specific advice.
  • Energy: 265
  • Fats: 15 g
  • Carbohydrates: 25 g
  • Proteins: 6 g