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4.67 from 3 votes
Creamy green bean casserole topped with crispy fried shallots in a rectangle baking dish with a wooden spoon scooping out a serving.
Green Bean Casserole
Prep Time
30 mins
Cook Time
45 mins
Total Time
1 hr 15 mins

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!

Course: Side Dish
Cuisine: American
Keyword: green bean casserole
Servings: 8 Servings
Calories: 407 kcal
  • 2 lbs green beans, ends trimmed and cut in half
Roasted Mushrooms
  • 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
Béchamel Sauce
  • 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
Crispy Shallots
  • 2 cups canola oil
  • 4 large shallots, thinly sliced and separated into rings
  • 3 Tbsp Wondra flour (or all purpose)
Green Beans
  1. 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.

Roasted Mushrooms
  1. Preheat oven to 425 degrees. Line a baking sheet with nonstick foil or parchment paper.

  2. Spread sliced mushrooms and thyme onto the baking sheet, drizzle with olive oil, and sprinkle with salt and pepper.

  3. Roast about 15 minutes or until golden brown. Reserve.
  4. Reduce oven temperature to 375 degrees.
Béchamel Sauce
  1. Melt butter in medium saucepan over medium heat. Add minced garlic and shallots and cook for 2 minutes.

  2. Add the flour and cook 2-3 minutes, stirring well. Pour in the milk, whisking constantly.

  3. Bring to a boil, then reduce to a simmer. Cook for about 5 minutes or until thickened, whisking frequently.

  4. Stir in nutmeg, soy sauce, lemon zest, lemon juice, Parmesan, salt, and pepper to taste.

Make the Casserole
  1. Spray a 13 x 9 inch baking pan with cooking spray.

  2. 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.

  3. Bake (at 375 degrees) for about 20 minutes or until hot and bubbly.

  4. While casserole is baking, fry the shallots.
Shallot Topping
  1. Heat canola oil in a heavy pot fitted with a deep fry thermometer to 375 degrees.

  2. Add Wondra flour to a large ziploc bag and sprinkle in shallots.
  3. Seal bag and shake vigorously until all shallots are evenly coated with flour.
  4. Remove the shallots, gently shaking off extra flour, and add half the shallots to the heated oil.

  5. Cook shallots in two batches until golden brown and crispy, about 3-4 minutes.
  6. Remove shallots from oil and allow to drain on a paper towel-lined plate. Sprinkle lightly with salt.

  7. 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!

Recipe Notes
  • 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.
Nutrition Facts
Green Bean Casserole
Amount Per Serving
Calories 407 Calories from Fat 252
% Daily Value*
Fat 28g43%
Saturated Fat 11g69%
Cholesterol 47mg16%
Sodium 286mg12%
Potassium 769mg22%
Carbohydrates 29g10%
Fiber 5g21%
Sugar 11g12%
Protein 12g24%
Vitamin A 1440IU29%
Vitamin C 19mg23%
Calcium 268mg27%
Iron 2.8mg16%
* Percent Daily Values are based on a 2000 calorie diet.