Healthy Green Bean Casserole

Baking dish filled with green bean casserole.

This Healthy Green Bean Casserole is a lighter alternative to the traditional green bean casserole but without any canned goods or fried french onions! It is made entirely from scratch with fresh green beans and mushrooms in a creamy sauce with an extra crispy onion topping!

Course Side, Side Dish

Cuisine American

Keyword Casserole, Green Bean Casserole, Healthy Green Bean Casserole, Thanksgiving

Prep Time 20

Cook Time 1

Servings servings

Calories 235kcal

Author Samantha Buckner

Ingredients

For the crispy onion topping:

2 medium yellow onions, thinly sliced
2 tablespoons olive oil
1 cup panko breadcrumbs
1/3 cup freshly grated parmesan cheese, fresh is best!
1/2 teaspoon salt, more or less, to taste
1/4 teaspoon black pepper, more or less, to taste
1/2 teaspoon garlic powder

For the green beans:

2 pounds fresh green beans, trimmed and cut into bite-sized pieces

For the mushrooms:

1 pound baby bella mushrooms, washed and sliced thin
2 tablespoons unsalted butter
1 teaspoon fresh thyme, or 1/3 teaspoon of dried
salt and pepper, to taste

For the sauce:

2 tablespoons unsalted butter
1/3 cup all-purpose flour, or GF all-purpose flour
2 cups unsalted vegetable stock, or chicken stock/broth
1 cup milk, dairy or dairy-free
1/3 cup freshly grated parmesan cheese
1/2 teaspoon garlic powder
1/2 teaspoon salt, more or less, to taste
1/4 teaspoon black pepper, more or less, to taste

Instructions

Crispy onion topping:

Preheat oven to 425 degrees F.
Line a baking sheet with parchment paper and set aside.
To a large mixing bowl, toss the onions with the olive oil to fully coat.
To a medium mixing bowl, combine the breadcrumbs, parmesan cheese, salt, pepper, and garlic powder.
Add the breadcrumb mixture to the onions and gently fold everything together. Spread out into an even layer onto the prepared baking sheet.
Bake for 15 minutes, stirring or flipping halfway through.
Remove from oven, set aside, and lower the temperature to 350 degrees F.

Green beans:

While the onions are cooking, bring a large pot of salted water to a boil. Add the green beans, cooking 3 minutes. Drain and rinse in very cold water to remove any heat to stop the cooking process. Drain well and pat dry with paper towels if needed.

Mushrooms:

Meanwhile, place a large saucepan over high heat with 2 tablespoons of butter. Once the butter is melted and bubbling, add the sliced mushrooms. Saute for 5-7 minutes or until all of the moisture has cooked out and they are golden brown. Season with salt, pepper, and fresh thyme.
Remove to a bowl or even the pot you used to boil the beans (one less dish to wash) and set aside.

Sauce:

Place the same saucepan over medium heat. Add 2 tablespoons of butter and once melted and starting to bubble, sprinkle in the flour, whisking until a paste forms.
Slowly poor in the stock, whisking consistenly and vigorously until no clumps remain. Pour in the milk and raise the temperature to medium-high heat to bring to a boil for 1 minute before reducing to a simmer for 3-5 minutes, stirring often until the sauce begins to thicken.
You want a thin, gravy-like consistency.
Turn off heat, add the parmesan cheese, salt, pepper, and garlic powder. Stir until the cheese has melted.

Putting it together:

Spray an 8x12 or 9x13 baking dish with nonstick cooking spray. Add the green beans and mushrooms.
Pour the sauce overtop and stir to coat.
Top with the onions, cover with aluminum foil and bake for 15-20 minutes. Remove foil and bake for an additional 5-10 minutes, keeping an eye on the onion topping.
Garnish with freshly cracked black pepper, additional parmesan cheese, and freshly chopped thyme. Serve hot.

Notes

To make gluten free: use gluten-free breadcrumbs and gluten-free all-purpose flour.

Vegetable stock: can swap for vegetable broth, chicken broth, or chicken stock.

Sodium: If using regular broth or stock (rather than unsalted), I recommend seasoning with salt, to taste.

Milk: We use cashew milk, but you can use heavy cream, half and half, regular milk, or another dairy-free alternative (although I cannot attest to the results with all dairy-free options).

Extra-crunchy onion topping: If the onions are not as crispy as you would like them to be, simply turn the oven to low broil and allow the topping to cook for 2-3 minutes. Keep an eye on it!

Nutrition