An overhead shot of green bean casserole on a plate.

The Best Green Bean Casserole Recipe

The Best Green Bean Casserole starts with fresh green beans, homemade mushroom cream sauce, and a crunchy bread crumb-fried onion topping.
Course Side Dish
Cuisine American
Keyword casserole, green beans, thanksgiving
Prep Time 10 minutes
Cook Time 45 minutes
Total Time 55 minutes
Servings 12 servings
Calories 366kcal
Author Meggan Hill


For the topping:

  • 4 slices white sandwich bread torn into quarters
  • 2 tablespoons butter softened
  • Salt and freshly ground black pepper
  • 3 cups canned fried onions (about 6 ounces)

For the casserole:

  • Salt and freshly ground black pepper
  • 2 pounds green beans ends trimmed, halved
  • 3 tablespoons butter
  • 1 pound white button mushrooms wiped clean and sliced or broken into pieces
  • 3 cloves garlic minced
  • 3 tablespoons all-purpose flour
  • 1 ½ cups chicken broth
  • 1 ½ cups heavy cream


To make the topping:

  • In a food processor or blender, pulse bread, butter, 1/4 teaspoon salt, and 1/8 teaspoon pepper until coarse crumbs form (about 10 pulses). Transfer to a large bowl. Add onions and toss to combine.

To make the casserole:

  • Adjust an oven rack to middle position and preheat oven to 425 degrees. In a Dutch oven or stock pot, bring 4 quarts water and 2 tablespoons salt to boil. Fill a large bowl with ice water.
  • Add green beans and cook until bright green and tender-crisp, about 6 minutes. Drain in colander and immediately transfer to ice water. Spread on paper towels to dry.
  • To the same pot, melt the butter over medium-high heat until foaming. Add mushrooms, garlic, 3/4 teaspoon salt, and 1/8 teaspoon pepper. Cook until the mushrooms have released most of their liquid, about 5 minutes.
  •  Stir in flour and cook for one minute. Whisk in broth, scraping up any brown bits from the bottom of the pan. Bring to a boil, whisking constantly.
  • Reduce heat to medium. Whisk in cream and simmer until the sauce has thickened and reduced to 3 1/2 cups, about 10 to 15 minutes. Season to taste with salt and pepper.
  • Add the green beans to the pot with the mushroom sauce and toss until evenly coated. Pour into a 3-quart or 9-inch by 13-inch baking dish. Sprinkle with topping.
  • Bake until the top is golden brown and the sauce is bubbling around the edges, about 15 minutes. Serve immediately.


  1. The bread crumb topping can be prepared ahead of time and stored in an air-tight container in the refrigerator. Combine with fried onions just before baking.
  2. The beans and sauce can be cooled and stored in a baking dish, covered with plastic wrap, in the refrigerator up to 24 hours in advance. Heat the casserole for 10 minutes in a 425-degree oven before adding the topping, then bake as directed. 
  3. To make half a batch, prepare in a 2-quart or 8-inch square baking dish. Reduce the sauce cooking time to about 6 minutes for 1 3/4 cups. Reduce the baking time to 10 minutes in Step 4.
  4. Adapted from Cook’s Illustrated Magazine, November & December 2006 issue.


Calories: 366kcal