Bubbling green bean casserole in a white ceramic baking dish with a golden crispy fried onion topping, photographed from above on a wooden table

Easy Green Bean Casserole with Crispy Fried Onions

Name: Easy Green Bean Casserole with Crispy Fried Onions
Prep time: 20 min
Cook time: 35 min
Total time: 55 min
Cuisine: American
Ingredients: 2 pounds fresh green beans, trimmed and cut into 2-inch pieces; 3 tablespoons unsalted butter; 8 ounces cremini or baby bella mushrooms, thinly sliced; 4 garlic cloves, minced; 3 tablespoons all-purpose flour; 1 cup chicken broth (or vegetable broth); 1 cup whole milk; 1/2 cup sour cream; 1 teaspoon soy sauce; 1/2 teaspoon onion powder; 1/2 teaspoon black pepper; 3/4 teaspoon kosher salt, plus more for blanching water; 2 1/2 cups crispy fried onions, divided (store-bought like French's, or homemade)

Published by Fork Around & Find Out Kitchen — presented in the Lila editorial voice. Editorial standards

Quick Answer

Green bean casserole is made by combining blanched green beans with a creamy mushroom sauce, topping with crispy fried onions, and baking at 350°F for 25-30 minutes until bubbly. You can use canned cream of mushroom soup for a quick version or make the sauce from scratch for significantly better flavor.

Jump to Recipe

Green bean casserole has survived generations of holiday tables on reputation alone, which is impressive considering how often it tastes like canned vegetables taking a bath in beige. The fix is not to turn it into fine dining. The fix is to give every layer a reason to be there: properly cooked green beans, a savory mushroom sauce with real depth, and a crisp onion topping that stays crisp long enough to matter.

The beans should still have structure when they go into the casserole because they will keep cooking in the oven. The sauce needs enough seasoning and mushroom flavor to coat them without turning soupy, and the fried onions belong on top where they can brown instead of dissolving into the filling. That sounds obvious, but casseroles have been getting away with suspicious behavior for decades because somebody covered the dish with foil and called it tradition.

When everything is balanced, the finished casserole has tender beans, creamy savory sauce, and crunchy onions in the same bite. It is familiar enough for the holiday table but flavorful enough that people actually take seconds on purpose—not because they are trying to be polite to whoever brought it.

Prep20 minutes

Cook35 minutes

Total55 minutes

Serves8 servings

DifficultyEasy

Ingredients

Servings

2 pounds fresh green beans, trimmed and cut into 2-inch pieces
3 tablespoons unsalted butter
8 ounces cremini or baby bella mushrooms, thinly sliced
4 garlic cloves, minced
3 tablespoons all-purpose flour
1 cup chicken broth (or vegetable broth)
1 cup whole milk
1/2 cup sour cream
1 teaspoon soy sauce
1/2 teaspoon onion powder
1/2 teaspoon black pepper
3/4 teaspoon kosher salt, plus more for blanching water
2 1/2 cups crispy fried onions, divided (store-bought like French's, or homemade)

Instructions

1Preheat your oven to 350°F. Grease a 9x13-inch baking dish and set aside.
2Bring a large pot of generously salted water to a boil. Add the green beans and blanch for 5 minutes — they should be bright green and just barely tender. Drain immediately and transfer to a bowl of ice water for 2 minutes to stop cooking. Drain again and pat dry. This step matters. Wet beans will make your sauce watery and the whole thing will slide around like it has no convictions.
3In a large oven-safe skillet or heavy-bottomed saucepan over medium heat, melt the butter. Add the sliced mushrooms in a single layer and let them cook undisturbed for 3 minutes before stirring. Cook another 2-3 minutes until mushrooms are golden and have released most of their moisture. Add the garlic and cook 1 minute more.
4Sprinkle the flour over the mushroom mixture and stir to coat. Cook the flour for 1 minute, stirring constantly — this cooks out the raw flour taste, which is the kind of detail that separates a good casserole from a mediocre one.
5Slowly pour in the chicken broth while whisking, then add the milk. Whisk until smooth. Bring to a gentle simmer over medium heat and cook, stirring frequently, for 4-5 minutes until the sauce thickens enough to coat the back of a spoon.
6Remove from heat. Stir in the sour cream, soy sauce, onion powder, salt, and pepper. Taste and adjust seasoning.
7Add the drained green beans to the sauce and stir to combine. Transfer the mixture to your prepared baking dish. Stir in 1 1/2 cups of the fried onions directly into the casserole.
8Top evenly with the remaining 1 cup of fried onions.
9Bake uncovered at 350°F for 25-30 minutes, until the sauce is bubbling around the edges and the onions on top are deep golden brown. Let rest 5 minutes before serving. Cook poultry until the thickest piece reaches 165°F on an instant-read thermometer.

Nutrition Information

Estimated per serving: 1 of 8 servings.

160Calories

6 gProtein

19 gCarbohydrates

9 gTotal Fat

5 gSaturated Fat

4 gFiber

9 gTotal Sugars

390 mgSodium

23 mgCholesterol

Estimated from the ingredients and quantities in this recipe using standard food-composition values. Brand choices, trimming, cooking loss, optional ingredients, and actual portion size can change the numbers. How we calculate nutrition estimates.

Pro Tips

Dry your green beans thoroughly after blanching. Moisture is the enemy of a thick sauce, and a watery casserole is a casserole that has given up on itself.
Don't skip the soy sauce — it adds a depth of flavor that makes people ask what your secret is, and your secret is one teaspoon of soy sauce, which is both anticlimactic and satisfying to reveal.
If your fried onions are browning too fast in the oven, tent the dish loosely with foil for the last 10 minutes. The ones on the sides will crisp; the ones in the middle will stay slightly softer, which is actually the correct distribution of textures.

Substitutions

fresh green beans → frozen green beans, thawed and patted dry Skip the blanching step. Thaw completely and remove as much moisture as possible or the sauce will thin out.

fresh green beans → canned green beans, well drained If you grew up on this version, no judgment. Skip blanching. They'll be softer, which some people specifically want.

homemade mushroom sauce → 2 cans (10.5 oz each) condensed cream of mushroom soup mixed with 1 cup milk The quick version. Stir together, add green beans, and proceed from step 7. It works well when you need the familiar shortcut without making the sauce from scratch.

whole milk → half-and-half Richer sauce. Fully recommended if you're making this for a holiday and you want people to remember it.

sour cream → cream cheese, softened Add 3 tablespoons softened cream cheese instead. Slightly tangier and thicker sauce. Very good.

chicken broth → vegetable broth Makes the dish vegetarian without any noticeable difference in flavor.

Storage Instructions

Store leftovers covered in the refrigerator for up to 4 days. The fried onion topping will soften overnight — reheat uncovered in a 350°F oven for 15-20 minutes to revive some crispness, or add a fresh handful of fried onions on top before reheating. Microwaving works but the topping will not recover its texture, and you have to be at peace with that.

Make Ahead

You can assemble the full casserole up to 24 hours ahead — make the sauce, combine with beans, transfer to the baking dish, but do NOT add the fried onion topping. Cover tightly and refrigerate. When ready to bake, add the fried onions to the top and bake at 350°F for 35-40 minutes (add 10 minutes since it's starting cold). Add the topping right before it goes in the oven, not before refrigerating.

Freezing

Yes. Freeze Green Bean Casserole tightly covered before or after baking, depending on which stage the recipe handles best. Thaw in the refrigerator, then bake or reheat until the center is thoroughly hot; add crisp toppings at the end when possible.