How to Make Green Bean Casserole With Real, Simple Ingredients

Green bean casserole has been a Thanksgiving favorite for generations, but the traditional shortcut recipe relies on ultra-processed condensed soup and packaged fried onions. This made-from-scratch version recreates that classic flavor without gluten or ultra-processed ingredients, and it has a dairy-free option, too.

However, don’t expect it to taste exactly like the canned mushroom soup version—it doesn’t. It’s much better—richer and more flavorful. It combines fresh green beans, a savory sauce made with deeply browned mushrooms, and onions tossed in rice flour, then fried in avocado oil. A splash of optional white wine adds a bright, sophisticated note that balances the mushrooms’ deep, earthy flavor.

Although it takes longer than opening cans, you can do most of the work ahead of time, leaving only baking for Thanksgiving Day.

Why Make Green Bean Casserole From Scratch?

Canned green beans can get mushy and lack vibrant color. Name-brand condensed cream of mushroom soup contains vegetable oils, modified cornstarch, wheat flour, soy protein concentrate, MSG, and other additives. Name-brand fried onions contain palm oil, wheat flour, dextrose, and salt.

Making this casserole from scratch gives you control over the ingredients and cooking oil without sacrificing the creamy mushroom sauce and crispy onion topping that make this holiday classic so popular.

As a bonus, the mushroom sauce can double as comforting soup—simply add another 2 cups of broth.

Make Ahead for an Easier Holiday

To make this up to four days in advance, assemble the casserole through the step before baking, then cover and refrigerate it. Store the fried onions separately, loosely covered at room temperature.

On Thanksgiving Day, or whatever day you’ll be enjoying it, bake the casserole until hot and bubbling, allowing extra time if it’s coming straight from the refrigerator. Add the onions during the final five minutes of baking to restore their crispness.

Keep in mind that the days spent refrigerated before baking reduce the recommended storage period for leftovers.

Green Bean Casserole

Fresh green beans in a rich, savory mushroom sauce are topped with golden, crispy fried onions for a comforting holiday classic made entirely from scratch without ultra-processed ingredients.

Prep Time: 1 hour

Cook Time: 1 hour, 30 minutes

Total Time: 2 hours

Servings: 8 to 10

Equipment Needed

Ingredients

Instructions

Step 1: Line a baking sheet with paper towels.

Step 2: In a deep skillet or Dutch oven, heat the avocado oil over medium to medium-high heat (about 5.5 on a 9-point scale) until hot but not smoking.

Step 3: While the oil heats, slice the onions thinly, using a mandoline if you have one. Chop enough of the slices to make 3/4 cup; set the chopped onion aside for the sauce. Cut the other slices in half.

Step 4: In a medium bowl, mix 1/2 cup of the rice flour and 1/4 teaspoon of the salt. Add the onion half-rings; toss to separate and coat evenly. If needed, add another 1 to 2 tablespoons of rice flour to coat all of the onion. Add one coated onion piece to the oil to test the temperature. It should sizzle steadily without browning immediately. Adjust the heat, if needed.

Step 5: Transfer some of the half-rings to the oil without stacking them. You’ll need to do this in batches. Fry, stirring occasionally, for about five minutes, until just golden brown; they will brown more in the oven.

Step 6: Using a slotted spatula, spider, or skimmer, transfer them to the prepared baking sheet. Repeat with the remaining onions, then set them all aside. While the onions fry, you can prep the green beans, mushrooms, and garlic, and measure the sauce ingredients, but watch the onions closely, as they can burn quickly.

Step 7: In a large saucepan, bring 4 cups of filtered water and 1/2 teaspoon salt to a boil. Add the green beans and blanch until bright green and barely tender, about three minutes. Drain, transfer to a bowl of ice water for two minutes, then drain very well and set aside.

Step 8: Preheat the oven to 350 degrees Fahrenheit. Grease your casserole or baking dish with avocado oil.

Step 9: Carefully pour off the oil from the skillet or Dutch oven into a heatproof container. Set aside to cool before discarding.

Step 10: Wipe out any remaining onion bits with a paper towel and add back 1 tablespoon of the oil. Adjust the heat to medium-high (6 on a 9-point scale), and add the chopped onions, mushrooms, and 1/2 teaspoon salt. Cook, stirring occasionally, for about 12 minutes, until the mushrooms have released all of their liquid and it has evaporated. The mushrooms should be deeply browned at this point. Do not rush this step; browning gives the sauce its savory mushroom flavor.

Step 11: Add the garlic and black pepper; cook, stirring constantly, until aromatic, about 30 seconds. Add the wine, if using, and cook for about four minutes, until it has mostly evaporated. Sprinkle the remaining 1/4 cup rice flour over the mushrooms. Cook, stirring constantly, for about two minutes, until well incorporated. Stir in the broth (including the wine replacement if not using wine) until fully incorporated and starting to thicken. Add the milk and stir until mixed and thickened, about one to two minutes.

Step 12: Add the green beans to the skillet mixture and toss until evenly coated with mushroom sauce. Transfer the mixture to the prepared casserole dish. Bake for 25 minutes, until hot and starting to bubble.

Step 13: Scatter as many of the fried onions over the top of the casserole as desired; bake another five minutes, until the casserole is bubbling throughout and the onions are deeply golden.

Storage: Cover and refrigerate any leftovers for up to four days, accounting for any days the assembled casserole was refrigerated before baking.

Frequently Asked Questions

Q: If I’m using nondairy milk, does the type matter?

A: Yes. Cashew milk has a naturally creamier consistency that works especially well in soups and sauces. Almond milk and other thinner nondairy milks also work, but the sauce may be slightly less creamy. Macadamia milk is another creamy option, although its distinctive flavor may come through in the finished casserole. Regardless, use a plain, unsweetened variety.

Q: Can I use frozen or canned green beans?

A: Fresh green beans provide the best crisp-tender texture, but frozen green beans are a reasonable substitute, although they may be softer. Thaw and drain them well before using. Canned green beans are already cooked, so skip the blanching step and expect a much softer texture.

Q: Can I use all-purpose wheat flour instead of rice flour?

A: You can if you don’t need the casserole to be gluten-free, but rice flour fries up crisper than wheat flour.