Recipe: Green Bean Casserole with Mushroom Béchamel & Crispy Onions

updated May 2, 2019
Green Bean Casserole with Mushroom Bechamel & Crispy Onions
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(Image credit: Nealey Dozier)

Way back in college, green bean casserole was my signature dish, canned cream of mushroom and all. (And to think, I actually considered myself quite the gourmet.) Even though my culinary repertoire has moved beyond recipes that include processed soup, that classic American casserole—with extra cheddar cheese and a heap of “fried” onions—is still my favorite part of Thanksgiving.

(Image credit: Nealey Dozier)

Because green bean casserole is one of those dishes that I eat so rarely, come holiday time I cherish its simple nostalgia in each and every bite. I have always been curious, though, about its supreme possibilities if made completely from-scratch. But those were only pipe dreams, since the Dozier family doesn’t take well to “new” or “unusual” dishes appearing on or near the Thanksgiving table. (Don’t even mention the time I tried to make a wild rice dressing to supplement mom’s cornbread stuffing. Oh the nerve!)

This year I am spending Turkey Day with my sister’s family in San Francisco, and their idea of the holiday is a bit different than the one I’m used to celebrating down here in the South. Delicious, yes, but traditional? Not exactly. So I figured I might as well use the next two weeks at home to fit in the classics before heading West to sample their bountiful California cuisine.

This was as good an opportunity as any to attempt my homemade green bean casserole because if it didn’t work, nobody would be present to shame me back to the can. I put together my mental list of what would pull the dish together: fresh green beans, a creamy mushroom béchamel, and crispy fried onions should come together well. And talk about doing the trick: I think I just discovered the holy grail of green bean casseroles!

Yes, it took a little a lot more time that the recipe on the back of the French’s box, but good things really do come to those who wait. I had a good feeling from the start, but I truly knew it was going to be wonderful when I couldn’t stop slurping the mushroom sauce straight from the bowl. The kicker, though, was the beer-battered sweet onions that found their way on top. Some might call that gilding the lily. I’d call it awesome!

I served the casserole to my parents alongside a juicy roasted chicken, lemony new potatoes, and caramelized Vidalias. It was a meal made in heaven, and definitely worth giving thanks for. So why wait until November 22nd? Food this fresh should be celebrated, and shared, all year long. And for that I am grateful.

(Image credit: Nealey Dozier)

Green Bean Casserole with Mushroom Bechamel & Crispy Onions

Serves 8 to 10

Nutritional Info


For the crispy onions:

  • Cooking oil, such as peanut or canola oil

  • 1 cup

    all-purpose flour or chickpea flour

  • 1/2 cup

    lager-style beer, plus more as needed

  • 1

    small sweet onion, sliced into very thin rings or half moons

  • Kosher salt

For the casserole:

  • 2 pounds

    green beans, ends removed and beans snapped in half

  • 6 tablespoons

    unsalted butter, divided

  • 1 pound

    baby portobello mushrooms, cleaned and diced

  • 1

    small sweet onion, diced

  • 4 cloves

    garlic, peeled and minced

  • 1/2 cup

    dry white wine

  • 1 cup

    whole milk

  • 1 cup

    heavy cream

  • 1 cup

    chicken stock

  • 1/4 cup

    plus 2 tablespoons all-purpose flour*

  • 1 teaspoon

    Worcestershire sauce

  • 1 teaspoon

    ground mustard powder

  • Kosher salt and pepper, to taste

  • 1 cup

    freshly grated sharp cheddar


  1. For the onions, fill a heavy Dutch oven or cast iron pot with a few inches of cooking oil. Heat over medium-high until the temperature reaches 375°F. Line a sheet pan with paper towels.

  2. In a medium-sized mixing bowl, combine the flour and beer to make a pancake-like batter (thick but still pourable), using more beer if needed. Toss the onions in the batter and mix to coat evenly. Add the onions, separating as necessary, to the hot oil and cook until fluffy and light golden brown. Remove onions using a spider or slotted spoon to the sheet pan. Season generously with salt and set aside. (Crispy onions can be made 2 days in advance; store in an airtight container.)

  3. To make the casserole, preheat oven to 350°F. Bring a large pot of salted water to a boil. Add beans and cook until deep green and tender, about 10 - 15 minutes. (I prefer my beans cooked until very tender, so I lean towards the latter time, but if you prefer more crisp-tender beans, cook for about 10 minutes, or less. The beans do not soften more in the casserole.) Drain and rinse with cool water.

  4. In a large Dutch oven or heavy pot, melt 2 tablespoons of butter on medium-high heat. Add the mushrooms and sauté until they start sweating liquid, about 4 minutes. Add the onion, garlic, and a pinch of salt. Continue cooking, stirring often, until softened, about 6 minutes. Add the wine and simmer until it evaporates, about 3 minutes. Remove the mushroom mixture to a separate bowl.

  5. Combine the milk, cream, and chicken stock in a large glass bowl and microwave until hot, about 2-3 minutes (or bring to a simmer in a saucepan). Melt the remaining 4 tablespoons butter in the Dutch oven over medium-low heat. Add the flour and whisk until creamy (and "raw" taste cooked out), about 2 minutes. Add the hot milk mixture and continue cooking, whisking frequently, until thickened, about 15 minutes. Whisk in Worcestershire sauce, mustard powder, and a generous amount of salt and pepper.

  6. Stir the mushroom mixture into the cream sauce and simmer, whisking frequently, for about 5 minutes for the flavors to marry. Taste and adjust the salt and pepper. (You want this to be on the salty side, because it will mellow once you add the green beans.)

  7. Stir the green beans into the mushroom sauce and toss to combine. Pour the green bean mixture into a large, buttered casserole dish (mine holds 2 quarts). Bake uncovered for 15 minutes. Add the grated cheddar and crispy onions and bake uncovered until cheese is melted, about 15 more minutes. Let stand for 10 minutes before serving.

Recipe Notes

*Gluten-free: To make this recipe gluten-free, use your favorite all-purpose gluten-free flour or chickpea flour in the casserole.

(Image credit: Apartment Therapy)

(Images: Nealey Dozier)