This is not your grandma's green bean casserole! Inspired by the casserole of my youth, but reimagined with fresh green beans, roasted wild mushrooms, creamy béchamel sauce, and a crispy shallot topping. This will become your favorite Thanksgiving side!
- 2 lbs green beans, ends trimmed and cut in half
- 8 oz shiitake mushrooms, stemmed and caps sliced
- 8 oz oyster mushrooms, large, central stem removed and cut into smaller pieces
- 8 oz cremini mushrooms, sliced
- 3 Tbsp extra virgin olive oil
- 10 thyme sprigs
- Kosher salt and pepper
- 4 oz unsalted butter (1 stick)
- 1 garlic clove, minced
- 1 large shallot, minced
- 1/3 cup all-purpose flour
- 3 cups whole milk
- 1/2 tsp freshly grated nutmeg
- 2 tsp soy sauce
- 1 tsp lemon zest
- 2 Tbsp lemon juice
- 3/4 cup Parmesan cheese, grated
- Kosher salt and pepper
- 2 cups canola oil
- 4 large shallots, thinly sliced and separated into rings
- 3 Tbsp Wondra flour (or all purpose)
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Bring a pot of salted water to a boil and add beans. Boil about 5 minutes or just until tender. Plunge beans into an ice bath and remove when cooled. Spread beans out on paper towels to dry.
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Preheat oven to 425 degrees. Line a baking sheet with nonstick foil or parchment paper.
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Spread sliced mushrooms and thyme onto the baking sheet, drizzle with olive oil, and sprinkle with salt and pepper.
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Roast about 15 minutes or until golden brown. Reserve.
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Reduce oven temperature to 375 degrees.
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Melt butter in medium saucepan over medium heat. Add minced garlic and shallots and cook for 2 minutes.
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Add the flour and cook 2-3 minutes, stirring well. Pour in the milk, whisking constantly.
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Bring to a boil, then reduce to a simmer. Cook for about 5 minutes or until thickened, whisking frequently.
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Stir in nutmeg, soy sauce, lemon zest, lemon juice, Parmesan, salt, and pepper to taste.
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Spray a 13 x 9 inch baking pan with cooking spray.
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Remove from the béchamel sauce from the heat and combine beans, mushrooms, and béchamel sauce in a large bowl. Stir well and then pour into the prepared pan.
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Bake (at 375 degrees) for about 20 minutes or until hot and bubbly.
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While casserole is baking, fry the shallots.
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Heat canola oil in a heavy pot fitted with a deep fry thermometer to 375 degrees.
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Add Wondra flour to a large ziploc bag and sprinkle in shallots.
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Seal bag and shake vigorously until all shallots are evenly coated with flour.
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Remove the shallots, gently shaking off extra flour, and add half the shallots to the heated oil.
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Cook shallots in two batches until golden brown and crispy, about 3-4 minutes.
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Remove shallots from oil and allow to drain on a paper towel-lined plate. Sprinkle lightly with salt.
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Top the heated casserole with crispy shallots and return to oven to bake for another 5 minutes. Watch to be sure shallots do not burn!
- This casserole (other than the crispy shallots) can be prepared, poured into the baking dish, covered tightly, and refrigerated 1-2 days in advance, and then baked just before serving.
- Béchamel sauce requires frequent whisking to prevent it from becoming lumpy or sticking to the saucepan.
- Blanch those green beans until they're just crisp/tender. They'll continue cooking in the oven.
- Use a light hand when seasoning with salt. Remember the sauce will have some saltiness from the soy sauce and parmesan.
- Wondra flour is a dream for frying the shallots up light and extra crisp.
- Keep a close eye on the casserole when you pop it into the oven after you add the shallot topping so it doesn't burn. Five minutes should be plenty.