Old-School Green Bean Casserole

Featured in: Hearty Comfort Dinners

This nostalgic green bean dish features tender green beans enveloped in a creamy sauce made from sautéed mushrooms, onions, garlic, and a smooth blend of milk, cream, and vegetable broth. The casserole is generously topped with crispy fried onions for a delightful crunch. Preparing it involves blanching green beans to preserve their vibrant color and texture, then combining them in a thickened mushroom base before baking until bubbling and golden. It’s an ideal comforting side that pairs wonderfully with roasted poultry.

Updated on Sun, 09 Nov 2025 16:02:00 GMT
Creamy Old-School Green Bean Casserole baked with crispy onions, a holiday classic.  Save
Creamy Old-School Green Bean Casserole baked with crispy onions, a holiday classic. | smokyfeast.com

Old-School Green Bean Casserole is a nostalgic creamy side dish featuring tender green beans savory mushrooms and crispy fried onions. It is a classic staple for holiday feasts and family dinners bringing back comforting memories and delicious flavors.

I first made this casserole for a family Thanksgiving and ever since it has become a must-have at our celebratory table. Everyone looks forward to the fresh green beans and the rich homemade mushroom sauce.

Ingredients

  • Fresh green beans: 900 g (2 lb) trimmed and cut into 5 cm (2-inch) pieces or use 900 g frozen cut green beans thawed and drained
  • Unsalted butter: 2 tbsp for sautéing
  • Cremini or button mushrooms: 250 g (9 oz) sliced
  • Yellow onion: 1 small finely chopped
  • Garlic cloves: 2 minced
  • All-purpose flour: 2 tbsp for thickening the sauce
  • 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 Mushroom Mixture:
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.
Make the 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 Green Beans & Sauce:
Add the drained green beans to the skillet and toss to coat evenly in the sauce.
Assemble the 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 & Serve:
Let cool for 5 minutes before serving.
Nostalgic Old-School Green Bean Casserole topped with golden fried onions, perfect for family dinners.  Save
Nostalgic Old-School Green Bean Casserole topped with golden fried onions, perfect for family dinners. | smokyfeast.com

Our family loves making this casserole together each year and it disappears quickly around the dinner table. It is especially cherished by the kids who adore the crispy onion topping.

Make-Ahead Tips

Assemble the casserole up to step 6 cover and refrigerate for up to 24 hours. Add the onions and bake before serving for ultimate freshness and crunch.

Serving Suggestions

Serve alongside roast turkey chicken or even a vegetarian entree. The creamy gravy complements hearty main dishes and the crispy onions add a delightful contrast.

Customization & Variations

For extra flavor add 50 g grated sharp cheddar or Gruyère cheese to the sauce. Swap out fresh green beans for frozen to save time or mix in a pinch of cayenne for gentle heat.

Savor the rich flavors of Old-School Green Bean Casserole, a creamy side dish delight. Save
Savor the rich flavors of Old-School Green Bean Casserole, a creamy side dish delight. | smokyfeast.com

Try this Old-School Green Bean Casserole for a holiday classic everyone will ask for again. Its nostalgic flavors and easy make-ahead steps make it a stress-free star at any table.

Kitchen Questions

How do I prepare the green beans for best texture?

Blanch the green beans in boiling salted water for 5 minutes, then immediately cool in ice water to keep them tender-crisp and vibrant.

Can I use frozen green beans instead of fresh?

Yes, thaw and drain frozen cut green beans before blanching to achieve the right texture for this dish.

What type of mushrooms work best here?

Cremini or button mushrooms provide a savory depth and hold their shape well when sautéed for the sauce.

How can I add more flavor to the sauce?

Grated sharp cheddar or Gruyère cheese mixed into the sauce adds a rich, savory note enhancing the dish’s creaminess.

What’s the purpose of crispy fried onions in this dish?

They add a contrasting crunchy texture and a burst of savory flavor that complements the creamy green beans and mushrooms.

Is it possible to prepare this dish ahead of time?

Yes, you can assemble up to the baking step, refrigerate for up to 24 hours, then add the fried onions and bake before serving.

Old-School Green Bean Casserole

Tender green beans cooked in a rich mushroom sauce topped with crispy fried onions for a comforting side.

Prep duration
15 min
Heat time
35 min
Complete duration
50 min
Created by Jackson Reed


Skill Level Easy

Heritage American

Output 6 Portions

Nutrition Labels Meat-Free

What You'll Need

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)

Method

Phase 01

Preheat oven: Set oven temperature to 350°F.

Phase 02

Cook green beans: Bring a large pot of salted water to a boil, add green beans and cook for 5 minutes until tender yet crisp. Drain and rinse under cold water to halt cooking. Set aside.

Phase 03

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

Phase 04

Prepare sauce: Sprinkle flour into skillet and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Simmer until sauce thickens, about 5 minutes. Season with salt, pepper, and nutmeg if using.

Phase 05

Combine beans with sauce: Add green beans to skillet and toss gently to coat thoroughly with the sauce.

Phase 06

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

Phase 07

Bake initial layer: Bake uncovered for 25 minutes until bubbling around edges.

Phase 08

Add topping and finish baking: Remove casserole from oven, evenly distribute remaining fried onions, and bake an additional 5-7 minutes until topping is golden and crisp.

Phase 09

Rest before serving: Allow casserole to rest for 5 minutes to set before serving.

Kitchen Tools

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

Allergy Details

Always review ingredients for potential allergens and seek professional medical guidance if unsure.
  • Contains milk (dairy), wheat (gluten in flour and fried onions), and possibly soy (in some fried onion products). Verify ingredient labels.

Nutrition Details (per portion)

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