Old-School Green Bean Casserole

Featured in: Vegetarian Soul Dishes

This comforting green bean side blends tender green beans with a savory mushroom sauce and crispy fried onions for texture. Fresh beans are briefly boiled to maintain brightness, then combined with a creamy butter-based sauce enriched with mushrooms, onions, and subtle spices. Topped generously with crispy fried onions, the dish is baked until bubbling and golden, offering warm, rich flavors perfect for festive meals or casual dinners alike.

Updated on Sun, 09 Nov 2025 13:49:00 GMT
Creamy Old-School Green Bean Casserole topped with crispy fried onions for added crunch. Pin It
Creamy Old-School Green Bean Casserole topped with crispy fried onions for added crunch. | sweetbatata.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 recipe brings back fond memories of family gatherings and festive dinners, always a favorite on the table.

Ingredients

  • Vegetables: 900 g (2 lb) fresh green beans, trimmed and cut into 5 cm (2-inch) pieces (or substitute with 900 g frozen cut green beans, thawed and drained)
  • Sauce Base: 2 tbsp unsalted butter, 250 g (9 oz) cremini or button mushrooms sliced, 1 small yellow onion finely chopped, 2 garlic cloves minced, 2 tbsp all-purpose flour, 240 ml (1 cup) whole milk, 120 ml (½ cup) heavy cream, 120 ml (½ cup) low-sodium vegetable broth, 1 tsp salt, ½ tsp black pepper, ½ tsp ground nutmeg (optional)
  • Topping: 150 g (1½ cups) crispy fried onions (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.
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 cooking for another 2-3 minutes until softened.
Make 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:
Add the drained green beans to the skillet and toss to coat evenly in the sauce.
Assemble:
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.
Serve:
Let cool for 5 minutes before serving.
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This dish has always been a centerpiece during our family holidays, evoking comfort and nostalgia at every bite.

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). Double-check labels for allergens.

Nutritional Information (per serving)

Calories: 265, Total Fat: 15 g, Carbohydrates: 25 g, Protein: 6 g

Savor the nostalgia of Old-School Green Bean Casserole, rich in flavors and textures. Pin It
Savor the nostalgia of Old-School Green Bean Casserole, rich in flavors and textures. | sweetbatata.com

This old-school green bean casserole perfectly balances creamy and crunchy textures for a timeless holiday classic.

Recipe Questions & Answers

Can frozen green beans be used?

Yes, thawed and drained frozen cut green beans work well as a convenient alternative to fresh beans.

How do I achieve crispy fried onions topping?

Using store-bought fried onions or homemade versions, sprinkle them on before baking to allow browning and a crunchy texture.

What can enhance the sauce flavor?

Adding grated sharp cheddar or Gruyère cheese to the sauce enriches the creamy mushroom base with extra depth.

Is nutmeg necessary in the sauce?

Nutmeg is optional but adds a subtle warm spice that complements the creamy sauce nicely.

Can this dish be prepared ahead?

Yes, assemble up to the baking step and refrigerate for up to 24 hours. Add onions and bake when ready.

Old-School Green Bean Casserole

Nostalgic creamy green beans with mushrooms and crispy fried onions, ideal for cozy family gatherings.

Prep Time
15 min
Cook Time
35 min
Overall Time
50 min
Created by Nora James


Skill Level Easy

Cuisine American

Makes 6 Portions

Dietary Details 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 ground black pepper
11 ½ tsp ground nutmeg (optional)

Topping

01 1½ cups crispy fried onions (store-bought or homemade)

Cooking Steps

Step 01

Preheat oven: Set the oven to 350°F.

Step 02

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

Step 03

Cook mushrooms, onion, and garlic: In a large skillet over medium heat, melt butter. Add mushrooms and sauté for 5-6 minutes until browned. Incorporate onion and garlic, cooking another 2-3 minutes until softened.

Step 04

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

Step 05

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

Step 06

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

Step 07

Bake first stage: Bake for 25 minutes until bubbling.

Step 08

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

Step 09

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

Equipment Needed

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

Allergy Notice

Check each ingredient for allergens and reach out to a healthcare professional if you have concerns.
  • Contains milk (dairy), wheat (gluten in flour and fried onions), and possible soy (in store-bought fried onions). Verify product labels.

Nutrition Information (per portion)

Sweetbatata only offers this for informational use. Please don't treat it as personalized medical advice.
  • Caloric Value: 265
  • Fats: 15 g
  • Carbohydrates: 25 g
  • Proteins: 6 g