Green Bean Casserole Crispy Onions (Printable)
Tender green beans in savory mushroom sauce with crispy fried onions, perfect for comforting side dishes.
# What You'll Need:
→ Vegetables
01 - 1.5 lbs fresh green beans, trimmed and cut into 2-inch pieces
02 - 1 small yellow onion, finely chopped
03 - 2 cloves garlic, minced
04 - 8 oz cremini or white mushrooms, sliced
→ Sauce
05 - 2 tbsp unsalted butter
06 - 2 tbsp all-purpose flour
07 - 1 cup vegetable broth
08 - 1 cup whole milk
09 - 0.5 cup heavy cream
10 - 0.5 tsp salt
11 - 0.25 tsp freshly ground black pepper
12 - 0.25 tsp ground nutmeg
13 - 1 tsp soy sauce
→ Topping
14 - 1.5 cups crispy fried onions
# How-To Steps:
01 - Preheat the oven to 375°F. Lightly grease a 9x13-inch baking dish with butter or cooking spray.
02 - Bring a large pot of salted water to a rolling boil. Add the green beans and blanch for 4 minutes until crisp-tender. Drain and immediately transfer to an ice bath to stop the cooking process. Drain again and set aside.
03 - In a large skillet over medium heat, melt the butter. Add the chopped onion and cook for 2 minutes until softened. Add the garlic and mushrooms; sauté for 5-6 minutes until the mushrooms release their moisture and begin to brown lightly.
04 - Sprinkle the flour over the vegetable mixture and stir constantly to coat; cook for 1 minute to remove raw flour taste. Gradually pour in the vegetable broth while stirring. Add the milk and heavy cream; bring to a gentle simmer. Cook for 4-5 minutes, stirring frequently, until the sauce thickens enough to coat the back of a spoon.
05 - Stir in the salt, pepper, nutmeg, and soy sauce for umami depth. Remove the skillet from heat.
06 - Add the blanched green beans and half of the crispy fried onions to the thickened sauce. Fold gently until the beans are evenly coated.
07 - Transfer the green bean mixture to the prepared baking dish, spreading it into an even layer. Sprinkle the remaining crispy fried onions evenly over the top.
08 - Bake uncovered for 20-25 minutes until the sauce is bubbling around the edges and the onion topping is golden brown and crispy.
09 - Allow the casserole to rest for 5 minutes before serving to let the sauce set slightly for easier serving.
# Expert Advice:
01 -
- That irresistible contrast between tender beans in creamy sauce and the satisfying crunch of golden onions on top
- A make ahead friendly dish that travels beautifully to potlucks and holiday gatherings
- The from scratch sauce puts canned soup versions to shame while still being simple enough for a weeknight
02 -
- Overcooking the beans during blanching is the fastest way to end up with mushy casserole, so watch that timer closely
- The sauce will seem thick at first but thin out as the vegetables release moisture during baking
- Room temperature casserole before baking ensures more even cooking than putting a cold dish straight into the oven
03 -
- Use a wide skillet when making the sauce so the liquid evaporates faster and you get that perfectly thick consistency more quickly
- Position your oven rack in the upper third position during the last 5 minutes of baking if you want extra crispy onion topping without burning