Creamy Green Bean Casserole with Mushrooms, Parmesan, and Crispy Onions Recipe
This classic Green Bean Casserole recipe features fresh green beans in a creamy mushroom sauce, topped with crispy fried onions and a parmesan-panko crust for a satisfying, flavorful side dish perfect for holiday dinners or family meals.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Total Time: 50 minutes
- Yield: 6 servings
- Category: Side Dish
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Ingredients
Scale
Vegetables
- 1 lb fresh green beans, rinsed, trimmed and halved
- 8 ounces cremini or white mushrooms, sliced
- 3 garlic cloves, minced
Dairy & Fats
- 3 tablespoons unsalted butter, divided
- 1 cup heavy cream
- 1/4 cup parmesan cheese, finely grated
Dry Ingredients
- 2 tablespoons flour
- 1/4 cup panko bread crumbs
- 2 cups fried onions, divided
- 1/2 teaspoon kosher salt
- 1/4 teaspoon pepper
Liquids
- 1 cup vegetable or chicken broth
Instructions
- Prepare Green Beans: Rinse, trim, and halve the fresh green beans. Blanch them briefly in boiling water for about 3-4 minutes until tender-crisp, then drain and set aside.
- Sauté Mushrooms and Garlic: In a large skillet, melt 2 tablespoons of unsalted butter over medium heat. Add the sliced mushrooms, kosher salt, and pepper. Cook for about 5-7 minutes until the mushrooms soften and release their juices. Add the minced garlic and cook for another minute until fragrant.
- Make the Roux and Sauce: Sprinkle 2 tablespoons of flour over the mushroom mixture, stirring constantly to coat the mushrooms and cook the flour for 1-2 minutes to remove the raw taste. Gradually whisk in 1 cup of vegetable or chicken broth, then add 1 cup of heavy cream. Simmer the sauce, stirring frequently, until it thickens, approximately 4-5 minutes.
- Combine and Assemble: Add the blanched green beans to the mushroom sauce, mixing gently to combine. Transfer the mixture to a greased 9×13 inch baking dish. Sprinkle 1 cup of fried onions evenly over the top.
- Prepare Topping: In a small bowl, mix the panko bread crumbs with the finely grated parmesan and remaining 1 tablespoon butter melted. Sprinkle this mixture evenly over the fried onions on top of the casserole.
- Bake: Preheat the oven to 350°F (175°C). Bake the casserole uncovered for 25-30 minutes, until the topping is golden brown and the casserole is bubbly.
- Finish with Crispy Onions: Remove the casserole from the oven and sprinkle the remaining 1 cup of fried onions on top for an extra crispy finish. Serve hot.
Notes
- For a vegetarian version, use vegetable broth and ensure the fried onions contain no animal products.
- To save time, use pre-washed trimmed green beans, but blanch them before cooking.
- Make sure to cook the flour in the roux to avoid a raw flour taste in the sauce.
- You can prepare the casserole a day ahead, assembling it and storing covered in the refrigerator—add the fried onions topping just before baking.
- If you prefer a richer flavor, substitute half the heavy cream with half-and-half or whole milk, but the sauce may be thinner.