The Food Lab: The Ultimate Homemade Green Bean Casserole

The Food Lab

Unraveling the mysteries of home cooking through science.

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[Photographs: Vicky Wasik. Video: Natalie Holt]

The classic Campbell's green bean casserole is a staple on many Thanksgiving tables. But there are easy ways to upgrade the out-of-the-can version. If you're intimidated by the length and number of steps in this recipe, bear in mind that you don't need to use the whole thing. Try canned fried onions instead of frying your own. Or, to make it even easier, stick with two cans of cream of mushroom soup instead of making your own creamy mushroom sauce.

Here's the deal: If the only thing you do is substitute real blanched green beans for the canned variety, you're giving your casserole a major upgrade. Make your own mushroom sauce out of real mushrooms instead of canned cream of mushroom soup, and you can proudly say good-bye to Sandra Lee. Go the whole nine yards and make the fried shallots yourself, though, and you can proclaim that "semi-homemade" is a thing of the past.

My fried shallots are inspired by Thai-style fried shallots, something that you should have on hand in your kitchen all the time. I make mine in batches of a couple pounds. (To cook more than what's called for in this recipe, just increase the amount of oil to keep them covered.) A mandoline makes quick work of the shallots, and yields perfectly thin and even slices. Simply add them to a pan or wok, cover with oil, turn your heat up to high, and stir. The shallots will soften and then turn a light golden brown, at which point you can strain them into a bowl. Be sure to reserve the oil, though—we'll be using it again in a minute.

Blot the strained shallots with paper towels until the towels appear dry. Once cooled, the shallots will keep in an airtight container for up to a month. Add them to sandwiches and soups, use them as a garnish for cooked meats, or just eat 'em out of hand, straight out of the jar.


For my homemade mushroom sauce, I start by smashing the mushrooms with a skillet. Not only is it an extremely satisfying procedure, but it creates imperfect chunks of mushrooms, just like you find in the canned stuff.

I sauté the mushrooms in that aromatic shallot oil, along with a cube of butter for some extra rich and nutty flavor. Once they've begun to sizzle, after about five to 10 minutes, I stir in some minced garlic, then add flour to thicken the base, stirring until it forms a light golden-blond roux.

Whisking in a mixture of heavy cream, chicken stock, lemon juice, and soy sauce adds richness, moisture, acidity, and a burst of umami that coaxes out the mushrooms' natural savory character. I bring the sauce to a boil, then simmer until its consistency is slightly thinner than pancake batter.


Using fresh green beans is hands down the simplest way to upgrade your casserole. For the brightest flavor and a crisp-tender texture, I blanch the trimmed beans in salted boiling water for five minutes, then shock them in an ice bath to halt the cooking process.

Assembling the casserole couldn't be simpler: Just combine the green beans, mushrooms, and a cup of the shallots in a bowl, and stir to evenly distribute all the ingredients. Transfer the mixture to a baking dish, bake at 350°F (180°C) for 15 to 20 minutes until it's hot and bubbly, and top with more shallots to serve.