Go Back
Green bean casserole in a white baking dish with creamy mushroom sauce and crispy fried onions on top

Green Bean Casserole From Scratch

Classic green bean casserole with a homemade mushroom cream sauce instead of canned soup, topped with crispy fried onions. Make-ahead friendly.
Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Servings: 8 servings
Course: Side Dish
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

  • 2 lb fresh green beans 900 g, trimmed and cut into 2-inch pieces
  • 3 tbsp butter
  • 8 oz cremini or button mushrooms 225 g, sliced
  • 1 small onion finely chopped
  • 3 garlic cloves minced
  • 1 tsp fresh thyme leaves or 1/2 tsp dried
  • 3 tbsp all-purpose flour
  • 1 cup vegetable or chicken broth 240 ml
  • 1 cup whole milk 240 ml
  • 0.5 cup heavy cream 120 ml, or more milk
  • 1 tsp salt adjust to taste
  • 0.5 tsp black pepper
  • 0.25 tsp ground nutmeg optional
  • 0.5 cup grated Parmesan optional
  • 2 cups crispy fried onions about one 6 oz (170 g) container, divided

Equipment

  • 1 Large pot
  • 1 Large skillet
  • 1 9x13-inch (23x33 cm) baking dish

Method
 

  1. Heat the oven to 375°F (190°C) and grease a 9x13-inch baking dish.
  2. Bring a large pot of well-salted water to a boil. Cook the green beans for 4 to 5 minutes, until bright green and just tender. Drain and plunge into a bowl of ice water to stop the cooking, then drain well.
  3. Melt the butter in a large skillet over medium-high heat. Add the mushrooms and cook for 6 to 7 minutes, until browned and their liquid has cooked off.
  4. Add the onion and cook for 3 minutes, then add the garlic and thyme and cook for 30 seconds.
  5. Sprinkle in the flour and stir for 1 minute. Slowly pour in the broth, stirring, then the milk and cream. Simmer for 4 to 5 minutes, stirring often, until thick and creamy. Season with salt, pepper and nutmeg, and stir in the Parmesan if using.
  6. Stir in the green beans and half of the fried onions, then spread everything in the baking dish.
  7. Bake for 20 minutes, until bubbling at the edges. Scatter the remaining fried onions on top and bake for 5 minutes more, until golden.

Notes

Make ahead: assemble without the fried onions, cover and refrigerate for up to 1 day. Bake for 30 to 35 minutes from cold, adding the last onions for the final 5 minutes.
Frozen beans: use 2 lb frozen cut green beans. Thaw and pat dry; there is no need to blanch them.
Vegetarian: use vegetable broth and a vegetarian Parmesan, or leave the cheese out.
Plan the whole meal: see our easy Thanksgiving menu with a day-by-day make-ahead plan.