Old-School Green Bean Casserole

Featured in: Southern Comfort

This comforting dish combines tender green beans with a rich mushroom sauce and crispy fried onion topping for a satisfying side. Fresh or thawed green beans are quickly blanched, then coated in a creamy blend of butter, mushrooms, onions, garlic, and a subtle hint of nutmeg. After baking, the casserole develops a golden, crunchy layer of fried onions that contrasts perfectly with the smooth sauce. Ideal for holiday feasts or family dinners, this easy-to-make classic captures the essence of home-style cooking.

Updated on Thu, 13 Nov 2025 10:45:00 GMT
Creamy Old-School Green Bean Casserole with golden crispy onions, perfect for a cozy Thanksgiving. Save
Creamy Old-School Green Bean Casserole with golden crispy onions, perfect for a cozy Thanksgiving. | epicurestates.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 celebrations around the table, especially during chilly evenings when comfort food brings everyone together.

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

Prep Oven:
Preheat the 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 but still bright green. Drain and rinse under cold water. Set aside.
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, cooking for another 2-3 minutes until softened.
Prepare Sauce:
Stir in flour and cook for 1 minute, stirring constantly. 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 to the skillet and toss to coat evenly in the sauce.
Assemble and Bake:
Transfer 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.
Serve:
Let cool for 5 minutes before serving.
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This was always my grandmother's go-to side for Thanksgiving, and now it's a staple at my own table during the holidays.

Make Ahead and Storage

You can prepare the casserole up to the point before adding fried onions, cover, and refrigerate for up to a day. Simply add the onions and bake when ready to serve. Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.

Serving Suggestions

Serve alongside roast turkey, chicken, or baked ham for festive dinners. It also pairs nicely with mashed potatoes and fresh cranberry sauce.

Flavor Variations

Add grated cheddar or Gruyère cheese to the sauce for extra richness. Incorporate a dash of cayenne for subtle heat or swap mushrooms for caramelized shallots.

A comforting, bubbling Old-School Green Bean Casserole, a classic American side dish ready to serve. Save
A comforting, bubbling Old-School Green Bean Casserole, a classic American side dish ready to serve. | epicurestates.com

Enjoy this classic casserole as a comforting centerpiece at your next gathering—guaranteed to bring smiles and second helpings.

Recipe FAQs

Can frozen green beans be used?

Yes, thawed and drained frozen green beans work well and save prep time without compromising texture.

How do I make the sauce thicker?

Cooking the butter, mushrooms, and flour before adding liquids helps create a smooth, thick sauce that coats the beans nicely.

Is it possible to add cheese?

Adding sharp cheddar or Gruyère cheese to the sauce enriches flavor and adds creaminess.

What’s the best way to keep the onions crispy?

Adding half the fried onions before baking and the rest near the end ensures the topping stays crunchy.

Can this dish be prepared ahead?

Yes, assemble up to step 6, refrigerate for up to 24 hours, then bake with onions before serving.

Old-School Green Bean Casserole

Creamy green beans with sautéed mushrooms and crispy fried onions—tradition in every bite.

Prep duration
15 min
Cook duration
35 min
Complete duration
50 min


Complexity Easy

Heritage American

Output 6 Portions

Dietary considerations Meat-free

Components

Vegetables

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

Directions

Phase 01

Preheat oven: Preheat the oven to 350°F.

Phase 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.

Phase 03

Cook mushrooms and aromatics: 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 and cook for 2-3 minutes until softened.

Phase 04

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

Phase 05

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

Phase 06

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

Phase 07

Bake casserole: Bake for 25 minutes until bubbling.

Phase 08

Add topping and finish baking: Remove from oven, distribute remaining fried onions on top, and bake for an additional 5 to 7 minutes until golden and crisp.

Phase 09

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

Necessary tools

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

Allergy details

Review each component for potential allergens and consult with healthcare professionals if you're uncertain.
  • Contains milk (dairy), wheat (gluten in flour and fried onions), and soy (possible in store-bought fried onions). Verify labels for allergens.

Nutritional information (each portion)

These values are offered as a general guide and shouldn't replace professional medical guidance.
  • Energy: 265
  • Fat: 15 g
  • Carbohydrates: 25 g
  • Protein: 6 g