Description
A classic Green Bean Casserole recipe featuring tender blanched green beans in a creamy mushroom sauce, topped with crispy French fried onions for a perfect holiday or family dinner side dish.
Ingredients
Scale
Green Beans
- 1½ pounds green beans, trimmed and halved
Mushroom Sauce
- 2 tablespoons extra-virgin olive oil
- 16 ounces cremini mushrooms, sliced
- 2 tablespoons tamari
- 4 garlic cloves, minced
- 2 tablespoons fresh thyme leaves
- ¼ cup all-purpose flour
- 3 cups milk, any kind
- 1½ teaspoons Dijon mustard
- ½ cup grated Parmesan cheese, plus more for sprinkling
- ¼ teaspoon freshly ground black pepper
Topping
- 1½ cups French fried onions, or homemade Crispy Baked Onions (see notes)
Instructions
- Preheat and prepare baking dish. Preheat the oven to 400°F. Lightly grease a 9×13-inch baking dish to prepare for assembling the casserole.
- Blanch green beans. Bring a large pot of salted water to a boil. Have a large bowl of ice water ready nearby. Add the trimmed and halved green beans to the boiling water and blanch for 4 minutes. Drain the beans and immediately immerse them in the ice water to stop cooking. Drain again and pat dry with a towel.
- Cook mushrooms. Heat the olive oil in a large skillet over medium heat. Add the sliced cremini mushrooms and cook until they become soft, about 8 to 10 minutes. Stir in the tamari, minced garlic, and fresh thyme leaves.
- Make mushroom sauce. Sprinkle the flour evenly over the mushroom mixture and stir well to incorporate. Gradually add the milk and Dijon mustard, stirring constantly to combine. Reduce heat to a simmer and cook the sauce, whisking often, until it thickens, approximately 15 to 20 minutes. Stir in the grated Parmesan cheese and freshly ground black pepper.
- Assemble casserole. Spread one-third of the mushroom sauce in the prepared baking dish. Layer the blanched green beans over the sauce, and then pour the remaining sauce evenly on top.
- Add topping and bake. Sprinkle the French fried onions or homemade crispy baked onions evenly over the casserole. Cover the dish with foil and bake for 10 minutes. Remove the foil and bake uncovered for another 10 minutes. If the onions begin to brown too quickly, cover the casserole again to prevent burning.
- Garnish and serve. Optionally sprinkle additional Parmesan cheese on top before serving. Serve the casserole hot for best flavor and texture.
Notes
- For homemade crispy baked onions: Preheat the oven to 450°F and line two large baking sheets with parchment paper. Thinly slice 2 medium yellow onions. Toss them in a bowl with 4 teaspoons olive oil, ½ cup all-purpose flour, 2 tablespoons panko bread crumbs, and ½ teaspoon sea salt. Spread evenly on the baking sheets and bake for 25 to 35 minutes, tossing every 10 minutes and rotating pans as needed, until lightly browned and crispy. Store at room temperature until ready to use.
- For a vegan version of the casserole, omit the Parmesan cheese and add extra salt to the mushroom sauce to enhance flavor.
- Use tamari as a gluten-free alternative to soy sauce to keep the recipe adaptable.
- Blanching the green beans helps retain their vibrant color and crisp-tender texture.
Nutrition
- Serving Size: 1 cup
- Calories: 220 kcal
- Sugar: 4 g
- Sodium: 450 mg
- Fat: 12 g
- Saturated Fat: 4 g
- Unsaturated Fat: 7 g
- Trans Fat: 0 g
- Carbohydrates: 18 g
- Fiber: 4 g
- Protein: 8 g
- Cholesterol: 15 mg
