Roasted Garlic Green Bean Casserole – Creamy, Crispy, Perfect
This elevated green bean casserole ditches the canned soup for a homemade cream sauce infused with roasted garlic, mushrooms, and gruyère. A crispy parmesan-panko topping makes it a standout holiday side dish.
- Prep Time: 25 minutes
- Cook Time: 1 hour 15 minutes
- Total Time: 1 hour 40 minutes
- Yield: 8–10 servings
- Category: Side Dish
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Ingredients
For the Roasted Garlic:
- 2 whole heads of garlic
- 2 tablespoons olive oil
- Salt and pepper to taste
For the Casserole:
- 2 pounds fresh green beans, trimmed
- 3 tablespoons butter
- 1 pound cremini or button mushrooms, sliced
- 1 medium yellow onion, diced
- 3 cloves garlic, minced (in addition to roasted)
- 3 tablespoons all-purpose flour
- 2 cups whole milk
- 1 cup chicken or vegetable broth
- 1 cup sour cream
- 1½ cups shredded gruyère or sharp cheddar cheese
- 1 teaspoon fresh thyme leaves
- Salt and pepper to taste
For the Topping:
- 1½ cups panko breadcrumbs
- 3 tablespoons melted butter
- ½ cup grated parmesan cheese
- ½ teaspoon garlic powder
Instructions
1. Preheat your oven to 400°F. Cut the top ¼ inch off each garlic head to expose the cloves.
2. Place them on a piece of foil, drizzle with olive oil, and season with salt and pepper. Wrap the foil around them tightly.
3. Roast for 40–45 minutes until the cloves are golden and soft. Let them cool, then squeeze the roasted cloves out of their skins and mash them into a paste.
4. Bring a large pot of salted water to a boil. Add the green beans and cook for 4–5 minutes until bright green and crisp-tender.
5. Drain and immediately plunge them into a bowl of ice water to stop the cooking. Drain again and set aside.
6. In a large skillet or Dutch oven, melt the butter over medium-high heat. Add the mushrooms and cook for 6–8 minutes until they’ve released their liquid and are starting to brown.
7. Add the diced onion and cook for another 3–4 minutes until softened. Stir in the minced garlic and cook for 30 seconds.
8. Sprinkle the flour over the vegetables and stir constantly for about 1 minute. Gradually whisk in the milk and broth, stirring constantly to prevent lumps.
9. Bring to a simmer and cook for 3–4 minutes until the sauce thickens. Remove from heat and stir in the mashed roasted garlic, sour cream, shredded cheese, and thyme.
10. Season generously with salt and pepper. Fold in the blanched green beans until everything is well coated.
11. Transfer the mixture to a 9×13-inch baking dish. In a small bowl, combine the panko, melted butter, parmesan, and garlic powder.
12. Sprinkle the breadcrumb mixture evenly over the casserole. Bake at 375°F for 25–30 minutes until the top is golden brown and the sauce is bubbling around the edges.
Notes
For a vegetarian version, use vegetable broth instead of chicken broth.
Gruyère adds a nutty flavor, but sharp white cheddar also works well.
You can roast the garlic up to 3 days ahead — store mashed cloves in an airtight container in the fridge.
This casserole can be assembled in advance and baked just before serving. Allow extra time if baking from cold.
To make gluten-free, substitute the flour with a gluten-free all-purpose blend and use gluten-free panko.