Best healthy green bean casserole

Step by Step

Step 1

Preheat the oven to 350ºF. Spray a 9×11-inch casserole dish and a standard-size baking sheet with nonstick cooking spray. Set both aside.

Step 2

In a large bowl, whisk the egg and water together. In a separate smaller bowl, mix the breadcrumbs, parmesan, salt, and pepper together.

Step 3

Slice 2 large onions – we used setting #4 on the mandoline (a sharp knife works, too). Add the sliced onions to the bowl with the egg mixture. Stir to coat the onions.

Step 4

Add the breadcrumb mixture to the onions. Gently fold everything together until the onions are well coated.

Step 5

Spread the onions onto the prepared baking sheet and set aside.

Step 6

Place the rinsed and trimmed green beans into the prepared casserole dish. Set aside.

Step 7

Heat the olive oil in a large saucepan set over medium/high heat. When the oil is fragrant, add the mushrooms and 1/8 teaspoon of salt. Sauté for 4-6 minutes. Remove the mushrooms from the heat and transfer to a separate bowl. Set aside.

Step 8

In the same saucepan, prepare the roux. Melt the butter over medium/high heat. Add the flour to butter and mix until a thick paste forms.

Step 9

Slowly pour in the milk while continually whisking the milk, butter, and flour together. Whisk until mixture is thick. Remove the saucepan from the heat.

Step 10

Add the broth, cooked mushrooms, and the remaining 1/8 teaspoon of salt to the roux. Mix well.

Step 11

Pour the roux over the green beans and toss (directly in the baking dish) so the beans are coated.

Step 12

Place both the green bean casserole and onions in the oven at the same time.

Step 13

Bake for 20 minutes. Toss the onions and bake for an additional 20 more minutes.

Step 14

After 40 minutes, remove the casserole from oven. For extra crispy onions, turn the oven to high broil and broil the onions for 3-5 minutes.*

Step 15

Once onions are crunchy, use a spatula to gently transfer onions to top the green bean casserole. Serve warm.

Tips and Warnings

Storage: Store leftover green bean casserole an airtight container in the refrigerator for up to 3 days.
Make Ahead Instructions: If you plan to make this green bean casserole ahead of time, prepare the mushroom gravy and toss with the uncooked green beans in the casserole dish. Tightly cover the casserole dish for up to 2 days – when ready to bake, follow the instructions in the recipe below. For best results, wait to make the onions until immediately prior to serving so they are perfectly crunchy!
Breadcrumbs: Plain or Italian breadcrumbs work, too.
Flour: Feel free to use all-purpose or gluten free flour instead of white whole wheat flour.
Gluten Free Option: For a gluten free green bean casserole, use certified GF breadcrumbs and GF flour.
Extra Crispy Onions: This step is optional, but highly recommended. All ovens are different, so make sure to keep an eye on your onions in the broiler!

Ingredient

Large egg

1 1
Large red onions

2 2
Water

29.57 ml 1.03 fl. ozs
Grated parmesan cheese

118.29 ml 4.14 fl. ozs
Olive oil

221.8 ml 7.76 fl. ozs
Vegetable broth

59.15 ml 2.07 fl. ozs
Unsalted butter

44.36 ml 1.55 fl. ozs
Salt

0.62 ml 0.02 fl. ozs
Fresh green beans

20 oz 566.99 g
2% milk

3548.82 ml 124.21 fl. ozs
Chopped cremini mushrooms

2 cups 473.18 ml
Ground black pepper

0.62 ml 0.02 fl. ozs
Sea salt

1.23 ml 0.04 fl. ozs
White whole wheat flour*

59.15 ml 2.07 fl. ozs
Whole wheat bread crumbs*

1 cup 236.59 ml
White whole wheat flour*

0.25 cup 0.25 cup

Amount Per Serving
	Calories	176 kcal
	Carbohydrates	17 g
	Protein	7 g
	Fat	10 g
	Fiber	3 g
	Sugar	6 g

View nutrition facts