Old-School Green Bean Classic

Featured in: Seasonal Treats

This old-school dish features tender green beans enveloped in a rich, creamy mushroom sauce with a touch of garlic and onion. It’s topped with golden, crispy fried onions for a delightful crunch. Easy to prepare and bake, it suits any holiday or family meal with its comforting flavors and satisfying textures. Variations with sharp cheddar or Gruyère can add a savory depth, making it versatile for different tastes.

Updated on Thu, 13 Nov 2025 14:31:00 GMT
Creamy, baked Old-School Green Bean Casserole with golden crispy onions, a comforting Thanksgiving side. Pin
Creamy, baked Old-School Green Bean Casserole with golden crispy onions, a comforting Thanksgiving side. | cinnamonnest.com

Old-School Green Bean Casserole is a nostalgic, creamy side dish featuring tender green beans, savory mushrooms, and crispy fried onions. This classic recipe brings warmth to holiday feasts and family dinners.

I first tasted this casserole at my grandmother's Thanksgiving table, where everyone looked forward to that golden, bubbling pan coming out of the oven. It has been a staple side dish for us ever since.

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

Prepare to bake:
Preheat the oven to 180°C (350°F).
Blanch the 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.
Make the sauce:
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 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 beans and sauce:
Add the drained green beans to the skillet and toss to coat evenly in the sauce.
Layer and bake:
Transfer the mixture to a 2-liter (2-quart) baking dish. Sprinkle half of the crispy fried onions on top.
Bake until bubbly:
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 before serving:
Let cool for 5 minutes before serving.
Pin
| cinnamonnest.com

Last November, my little cousins insisted on helping sprinkle the fried onions before we started baking, making this dish even more special at our family gathering.

Serving Suggestions

This casserole pairs perfectly with roast turkey or chicken and makes a just-right companion for mashed potatoes or stuffing.

Make-Ahead Tips

Prepare up to baking and refrigerate for up to 24 hours. Top with the onions and bake when ready to serve for ultimate freshness.

Allergen Notes

Check fried onion and broth labels for hidden allergens such as soy or additional wheat. This recipe is vegetarian if you use vegetable broth.

This homemade Old-School Green Bean Casserole shows off tender green beans in a rich, mushroom-based sauce. Pin
This homemade Old-School Green Bean Casserole shows off tender green beans in a rich, mushroom-based sauce. | cinnamonnest.com

Enjoy this classic green bean casserole at your next celebration. The creamy mushroom sauce and crispy onions guarantee smiles every time.

Recipe FAQ

Can I use frozen green beans?

Yes, frozen cut green beans work well if thawed and drained properly before cooking to maintain texture.

How do I get the fried onions crispy?

Adding the onions midway through baking and again at the end helps them stay golden and crunchy.

Can I prepare this dish in advance?

Absolutely, assemble the casserole up to step 6 and refrigerate for up to 24 hours before baking with the onions.

What cheese can enhance the sauce?

Sharp cheddar or Gruyère grated into the sauce adds a rich, savory flavor boost.

How do I prevent the green beans from overcooking?

Blanch green beans until just tender and rinse under cold water to stop cooking and keep them bright.

Old-School Green Bean Classic

Tender green beans in a creamy mushroom sauce topped with crispy onions, ideal for holiday dinners.

Prep duration
15 min
Cooking duration
35 min
Total duration
50 min

Category Seasonal Treats

Difficulty Easy

Origin American

Yield 6 Servings

Dietary requirements Vegetarian

Ingredients

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

Step 01

Preheat Oven: Preheat the oven to 350°F.

Step 02

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 halt cooking. Set aside.

Step 03

Prepare Sauce: In a large skillet over medium heat, melt the butter. Add mushrooms and sauté for 5-6 minutes until tender and browned. Add onion and garlic, cooking for an additional 2-3 minutes until softened.

Step 04

Thicken Sauce: Stir in the 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.

Step 05

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

Step 06

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

Step 07

Bake First Stage: Bake in the preheated oven for 25 minutes until bubbling.

Step 08

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

Step 09

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

Necessary tools

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

Allergy information

Review ingredients carefully for potential allergens and consult with a healthcare provider if you're uncertain.
  • Contains milk (dairy), wheat (gluten in flour and fried onions), and possibly soy in store-bought fried onions.

Nutritional information (per serving)

These values are approximate guidelines only and shouldn't replace professional medical advice.
  • Calories: 265
  • Fat: 15 g
  • Carbs: 25 g
  • Protein: 6 g