Old-School Green Bean Casserole

Featured in: Classic Family Dinners

This dish features tender green beans enveloped in a rich, creamy sauce made from butter, mushrooms, onion, garlic, and cream, thickened with flour and broth. The casserole is topped generously with crispy fried onions, baked to golden perfection, giving a delightful contrast of textures. Ideal for festive dinners or comforting family meals, it brings nostalgic flavors with an easy preparation and moderate cooking time, perfect for serving six guests. Variations include adding sharp cheddar or Gruyère for extra richness.

Updated on Thu, 13 Nov 2025 16:17:00 GMT
Classic Old-School Green Bean Casserole, topped with crispy onions, bubbling hot from the oven. Pin
Classic Old-School Green Bean Casserole, topped with crispy onions, bubbling hot from the oven. | panpatriot.com

Old-School Green Bean Casserole brings back all the classic flavors of this nostalgic, creamy side dish. Tender green beans mix with savory mushrooms and crispy fried onions to create a timeless favorite for holiday feasts and family dinners.

I still remember the first time I made this casserole for my family: the unmistakable smell of baked onions and creamy sauce instantly brought everyone to the kitchen. The recipe became a cherished holiday ritual that we look forward to year after year.

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 for sautéing vegetables
  • Cremini or Button Mushrooms: 250 g (9 oz) sliced
  • Yellow Onion: 1 small, finely chopped
  • Garlic Cloves: 2, minced
  • All-Purpose Flour: 2 tbsp to thicken 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: ½ tsp (optional)
  • Crispy Fried Onions: 150 g (1½ cups), store-bought or homemade

Instructions

Preheat Oven:
Set oven to 180°C (350°F).
Blanch Green Beans:
Boil green beans in salted water for 5 minutes until bright green. Drain and rinse under cold water. Set aside.
Sauté Vegetables:
Melt butter in a large skillet over medium heat. Add mushrooms and cook for 5-6 minutes until tender and browned. Add chopped onion and garlic, cook for 2-3 minutes more.
Make Sauce:
Stir in flour and cook for 1 minute, stirring. Slowly whisk in milk, cream, and broth. Simmer and cook until sauce thickens, about 5 minutes. Season with salt, pepper, and nutmeg.
Combine Beans and Sauce:
Add drained beans to skillet. Toss to coat evenly.
Assemble and Bake:
Place mixture in a 2-liter (2-quart) baking dish. Top with half fried onions.
Bake:
Bake for 25 minutes until bubbling. Add remaining onions. Bake 5-7 minutes more until golden.
Serve:
Let cool for 5 minutes before serving.
A creamy, savory bowl of homemade Old-School Green Bean Casserole with tender green beans and mushrooms. Pin
A creamy, savory bowl of homemade Old-School Green Bean Casserole with tender green beans and mushrooms. | panpatriot.com

This casserole is always requested at our big family gatherings—the crispy topping is everyone's favorite part. Sharing it at our table is a tradition we treasure each year.

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). Always check labels for store-bought ingredients.

Nutritional Information

Per serving: 265 calories, 15 g total fat, 25 g carbohydrates, 6 g protein

Enjoy a warm serving of Old-School Green Bean Casserole, a comforting side dish with a rich sauce. Pin
Enjoy a warm serving of Old-School Green Bean Casserole, a comforting side dish with a rich sauce. | panpatriot.com

Make this old-school classic and watch everyone return for seconds. The blend of creamy sauce and crispy onions makes it an unbeatable crowd-pleaser.

Recipe Questions

How do I ensure the green beans stay tender?

Blanch green beans in boiling salted water for about 5 minutes until tender yet firm, then immediately rinse with cold water to stop cooking and preserve color.

Can I use frozen green beans instead of fresh?

Yes, thaw and drain frozen green beans thoroughly before using to avoid excess moisture in the casserole.

What’s the best way to achieve a crispy topping?

Sprinkle fried onions halfway through baking, then add more on top and bake until golden and crisp for perfect texture contrast.

Can I prepare this dish ahead of time?

Assemble through the step before adding fried onions and refrigerate for up to 24 hours; add onions just before baking to maintain crispness.

How can I add more depth of flavor?

Incorporate 50 g grated sharp cheddar or Gruyère into the creamy sauce for a richer, more complex taste.

Old-School Green Bean Casserole

Tender green beans baked in creamy mushroom sauce with a crispy fried onion topping.

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


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

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 to halt cooking. Set aside.

Step 03

Sauté mushrooms, onion, and garlic: In a large skillet over medium heat, melt butter. Add mushrooms and cook 5 to 6 minutes until tender and browned. Add onion and garlic; cook 2 to 3 minutes until softened.

Step 04

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

Step 05

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

Step 06

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

Step 07

Bake casserole: Bake for 25 minutes until bubbling. Remove from oven, top with remaining fried onions, and bake 5 to 7 minutes more until golden and crisp.

Step 08

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 information

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

Nutrition facts (per portion)

These values are estimates only and shouldn't replace professional medical guidance.
  • Calories: 265
  • Fat: 15 g
  • Carbohydrates: 25 g
  • Protein: 6 g