Easy & Healthy Green Bean Casserole Recipe

One of our favorite side dishes at the Thanksgiving table is the green bean casserole. We wish we could eat it all year long. But unfortunately, typical green bean casseroles are too heavy and unhealthy with the added cream, butter, cream of mushroom soup, and fried onions to enjoy on a regular basis outside of the holiday season. While in theory we could indulge in green bean casserole anytime our hearts desired, we are adults after all, and it's just not the healthiest decision.

That's why we're so grateful that recipe developer and registered dietitian nutritionist, Kristen Carli, MS, RD, created this healthy green bean casserole recipe. Using baked onions, homemade roux, and less excess cream, butter, and cream of mushroom soup, this recipe is one we feel okay to indulge in on a regular basis.

Keep reading to see our step-by-step guide on how to make this healthy green bean casserole at home.

To make this healthy green bean casserole, start by gathering the ingredients. You will need yellow onions, olive oil, breadcrumbs, flour, salt, green beans, unsalted butter, baby bella mushrooms, pepper, vegetable broth, minced garlic, and parmesan cheese. 

And while you're in prepping mode, go ahead and preheat the oven to 425 F and spray a large baking sheet with nonstick cooking spray.

The first step involves baking the onions. While most green bean casseroles call for fried onions, we'll be baking ours to be a bit healthier. In a large bowl, add the sliced onions, oil, breadcrumbs, ½ cup flour, and ½ teaspoon salt. Use tongs to mix the ingredients until well-combined. Then, pour the coated onions onto a baking sheet. Bake in the oven for 20 minutes before removing them from the oven and setting them aside. Lower the oven's heat to 350 F.

In a large skillet over medium heat, melt 2 tablespoons butter. Once melted, add in the mushrooms, 1 teaspoon salt, and ½ teaspoon pepper. Sauté the mushrooms for about 8 minutes, until the mushrooms shrink in size and darken in color. Then, transfer the mushrooms to a large bowl.

In the same hot skillet, add the remaining 2 tablespoons butter. Once melted, add in the last ⅓ cup flour. Using a whisk, mix to combine. Add the broth and whisk continuously over medium heat. The roux will begin to thicken and the lumps will begin to disappear. Simmer for 5 minutes.

In a large bowl, add the green beans, the sautéed mushrooms, and ½ the baked onions. Add the minced garlic and grated parmesan cheese. Using tongs, mix to combine. Then, pour this mixture into a 9x13-inch baking dish that's been sprayed with nonstick cooking spray. Top this mixture with the roux. Cover the dish with foil and bake for 30 minutes at 350 F.

Once the time is up, remove the baking dish from the oven. Remove the foil and add the remaining baked onions on top. Place the baking dish back in the oven for 10 minutes at 350 F. When the timer dings, remove the baking dish from the oven and allow the casserole to cool for at least 10 minutes before serving.