Old School Green Bean Casserole (Printable)

Tender green beans in creamy mushroom sauce topped with crispy fried onions, perfect for festive meals.

# Required Ingredients:

→ Vegetables

01 - 2 pounds fresh green beans, trimmed and cut into 2-inch pieces (or frozen cut green beans, thawed and drained)

→ Sauce Base

02 - 2 tablespoons unsalted butter
03 - 9 ounces cremini or button mushrooms, sliced
04 - 1 small yellow onion, finely chopped
05 - 2 garlic cloves, minced
06 - 2 tablespoons all-purpose flour
07 - 1 cup whole milk
08 - ½ cup heavy cream
09 - ½ cup low-sodium vegetable broth
10 - 1 teaspoon salt
11 - ½ teaspoon black pepper
12 - ½ teaspoon ground nutmeg (optional)

→ Topping

13 - 1½ cups crispy fried onions, store-bought or homemade

# Preparation Steps:

01 - Preheat the oven to 350°F.
02 - 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 under cold water to stop cooking. Set aside.
03 - In a large skillet over medium heat, melt butter. Add mushrooms and sauté for 5-6 minutes until tender and browned. Add onion and garlic; cook 2-3 minutes until softened.
04 - Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Simmer gently until sauce thickens, about 5 minutes. Season with salt, pepper, and nutmeg if using.
05 - Add drained green beans to the skillet and toss to coat evenly with the sauce.
06 - Transfer mixture to a 2-quart baking dish. Sprinkle half the crispy fried onions evenly on top.
07 - Bake for 25 minutes until the mixture is bubbling.
08 - Remove from oven, top with remaining fried onions, and bake for an additional 5 to 7 minutes until golden and crisp.
09 - Allow to cool for 5 minutes before serving.

# Expert Suggestions:

01 -
  • Crowd-pleasing comfort food for holidays and potlucks
  • Uses fresh or frozen green beans for flexibility
02 -
  • Fried onions may contain soy and gluten; check ingredient labels if needed
  • Casserole can be assembled ahead and baked just before serving
03 -
  • Add sharp cheddar or Gruyère cheese for extra richness
  • Substitute with frozen green beans if fresh are unavailable
Go Back