Classic Green Bean Casserole (Printable Version)

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

# What You'll Need:

→ Vegetables

01 - 1 lb fresh green beans, trimmed and cut into 2-inch pieces (or 1 lb frozen, thawed)
02 - 1 small yellow onion, finely chopped
03 - 2 cloves garlic, minced
04 - 8 oz cremini or button mushrooms, sliced

→ Sauce

05 - 2 tbsp unsalted butter
06 - 2 tbsp all-purpose flour
07 - 1 cup whole milk
08 - 1/2 cup low-sodium vegetable broth
09 - 1/2 cup sour cream
10 - 1/2 tsp salt
11 - 1/4 tsp black pepper
12 - 1/4 tsp ground nutmeg

→ Topping

13 - 1 1/2 cups crispy fried onions (store-bought or homemade)

# Directions:

01 - Preheat the oven to 350°F.
02 - Bring a large pot of salted water to a boil. Add green beans and cook for 4 to 5 minutes until bright green and just tender. Drain and transfer immediately to a bowl of ice water. Drain again and set aside.
03 - In a large skillet over medium heat, melt butter. Add chopped onion and cook for 2 to 3 minutes until softened. Add garlic and mushrooms; cook for 5 minutes until mushrooms are tender and liquid has evaporated.
04 - Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk and vegetable broth. Cook, stirring, until sauce thickens, about 3 to 4 minutes.
05 - Remove skillet from heat. Stir in sour cream, salt, pepper, and nutmeg until the sauce is smooth.
06 - Add drained green beans to the sauce and mix to coat evenly.
07 - Transfer mixture to a greased 2-quart baking dish. Sprinkle 1 cup of crispy fried onions evenly on top.
08 - Bake for 25 minutes until the casserole is bubbling.
09 - Remove from oven, top with remaining fried onions, and bake an additional 5 minutes until golden brown.
10 - Let rest for 5 minutes before serving.

# Expert Advice:

01 -
  • It feels restaurant-quality but takes less time than you'd think.
  • The combination of creamy, savory, and crispy textures keeps people coming back for seconds.
  • You can prep it hours ahead and just pop it in the oven, which means one less thing to worry about when hosting.
02 -
  • Don't skip the ice bath after blanching the green beans; it's the difference between vegetables that stay vibrant and ones that turn olive-colored and soft.
  • If your sauce breaks or looks grainy after adding sour cream, you added it while the pan was too hot. Start over with a fresh batch of cream and patience.
03 -
  • Toast your fried onions in a dry skillet for a minute or two before adding them to intensify their flavor and ensure maximum crunch.
  • Use low-sodium broth so you control the salt level; it's easier to add more salt than to fix something that's oversalted.
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