Can I use frozen green beans instead of fresh?

Yes, you can! Thaw them completely and pat them dry first. Skip the blanching step, but be aware that frozen beans will have a softer texture than fresh in the final dish. For the best texture with frozen beans, add them directly to the casserole without pre-cooking.

How do I prevent my sauce from becoming lumpy?

The key is to add cold milk slowly to your roux, whisking constantly. If you do get lumps, don't panic! Simply blend the sauce with an immersion blender or regular blender until smooth, then return it to the pan to continue thickening.

Can I make this casserole completely ahead of time?

Absolutely! Prepare everything except the panko topping up to two days ahead. Store in the refrigerator, covered. When ready to serve, bring to room temperature for 30 minutes, add the topping, and broil until bubbling and golden.

Why does my casserole turn out watery?

This usually happens if the green beans weren't dried thoroughly after blanching or if the sauce wasn't thickened enough. Make sure to really pat those beans dry and let the sauce reduce until it coats the back of a spoon before adding the Greek yogurt.

Healthy Green Bean Casserole Recipe

Description

This Healthy Green Bean Casserole is a lighter, nutrient-packed twist on the classic holiday side, featuring crisp green beans, savory sautéed mushrooms, a creamy Greek yogurt sauce, and a crunchy panko-Parmesan topping. Perfect for gatherings, it delivers comfort without the heaviness of traditional casseroles.

Ingredients

Units Scale

Topping

1/2 cup whole wheat panko breadcrumbs
1/4 cup freshly grated Parmesan cheese
2 tablespoons chopped fresh parsley (plus extra for garnish)
2 tablespoons extra-virgin olive oil

Green Bean & Sauce

2 1/2 pounds green beans, trimmed
1 medium onion, very thinly sliced
8 ounces baby bella (cremini) mushrooms, sliced
2 tablespoons extra-virgin olive oil (remaining)
3 tablespoons all-purpose flour
2 cups 2% milk
1 teaspoon kosher salt
1/2 teaspoon ground black pepper
1/8 teaspoon ground nutmeg
7 ounces 2% Greek yogurt

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Instructions

Preheat & Prepare Dish: Position a rack in the upper third of the oven and preheat the broiler. Lightly coat a 2-quart, broiler-safe baking dish with nonstick spray to prevent sticking.
Make Topping: In a small bowl, combine the panko breadcrumbs, grated Parmesan, chopped parsley, and 2 tablespoons olive oil. Mix thoroughly and set aside. This mixture will create a crunchy, savory topping for the casserole.
Blanch Green Beans: Bring a large pot of water to a boil. Prepare a bowl with ice water and set out a clean kitchen towel. Cook green beans in boiling water for about 3 minutes until just crisp-tender. Immediately transfer the beans to the ice water to stop the cooking, then drain well and place on the kitchen towel. Lightly pat dry to remove excess moisture.
Cook Mushrooms and Onion: In a large, wide saucepan, heat 1 tablespoon olive oil over medium heat. Add the sliced onions and mushrooms. Sauté, stirring frequently, until onions are soft and golden and mushrooms are browned and have released their liquid, about 15 minutes. Add the remaining 1 tablespoon olive oil.
Add Flour: Sprinkle the flour over the sautéed vegetables. Cook for another 1–2 minutes, stirring constantly, until the flour is fully combined and turns a light golden color, with no white spots remaining.
Make Sauce: Gradually add the milk, a little at a time, stirring between additions to prevent lumps. Turn the heat to medium-high and add the salt, pepper, and nutmeg. Stir continuously, letting the sauce bubble and thicken, about 8–10 minutes, until it reaches a creamy gravy consistency. Remove from the heat and stir in the Greek yogurt until the sauce is smooth.
Assemble Casserole: Place half the green beans in the prepared baking dish. Evenly spread half the sauce over the beans. Add the remaining green beans, then top with the rest of the sauce. Sprinkle the reserved breadcrumb mixture evenly over the top.
Broil: Place the casserole under the broiler. Broil, watching closely, for 1 to 3 minutes until the top is bubbling and golden brown. Do not walk away, as it can brown quickly.
Rest & Serve: Let the casserole stand for 10 minutes before serving. Garnish with additional chopped parsley for a fresh, colorful touch.

Notes

Don’t use plain white mushrooms; baby bellas add more flavor.
Make sure green beans are just barely tender after blanching for the best texture.
Broil briefly and monitor carefully to prevent burning.
This dish can be prepped ahead: assemble the casserole and topping separately, then broil when ready to serve.
Greek yogurt keeps the sauce creamy while reducing fat compared to traditional recipes.

Nutrition

Serving Size: 1/10th of casserole
Calories: 155
Sugar: 5g
Sodium: 380mg
Fat: 8g
Saturated Fat: 2g
Unsaturated Fat: 5g
Trans Fat: 0g
Carbohydrates: 15g
Fiber: 4g
Protein: 8g
Cholesterol: 7mg