Green Bean Casserole
Serves 8
This green bean casserole recipe is a delicious homemade version of the classic holiday side dish. It's made with fresh green beans and a from-scratch creamy mushroom sauce. I like to top it with crispy baked onions (see the notes below!), but store-bought crispy fried onions work here too.
Ingredients
- 1½ pounds green beans, trimmed and halved
- 2 tablespoons extra-virgin olive oil
- 16 ounces cremini mushrooms, sliced
- 2 tablespoons tamari
- 4 garlic cloves, minced
- 2 tablespoons fresh thyme leaves
- ¼ cup all-purpose flour
- 3 cups milk, any kind
- 1½ teaspoons Dijon mustard
- ½ cup grated Parmesan cheese, plus more for sprinkling
- ¼ teaspoon freshly ground black pepper
- 1½ cups french fried onions, or homemade Crispy Baked Onions (see recipe notes)
Instructions
- Preheat the oven to 400°F. Lightly grease a 9x13-inch baking dish.
- Bring a large pot of salted water to a boil and set a large bowl of ice water nearby. Drop the green beans into the boiling water and blanch for 4 minutes. Immediately transfer to the ice water to stop the cooking process. Drain and transfer to a towel to dry.
- Heat the olive oil in a large skillet over medium heat. Add the mushrooms and cook until soft, 8 to 10 minutes. Stir in the tamari, garlic, and thyme. Sprinkle the flour over the mushrooms and stir again. Add the milk and mustard and stir to combine. Simmer until thickened, whisking often, 15 to 20 minutes. Stir in the Parmesan cheese and pepper.
- Spread ⅓ of the sauce at the bottom of the baking dish. Spread the green beans evenly on top, then top with the remaining sauce. Sprinkle on the onions and bake, covered, for 10 minutes. Uncover and bake for 10 more minutes. If the onions start to brown too much, cover the dish for the remainder of the baking time. Garnish with sprinkles of Parmesan, if desired. Serve hot.
Notes
For the Crispy Baked Onions: Preheat the oven to 450°F. Line 2 large baking sheets with parchment paper.
Thinly slice 2 medium yellow onions. In a large bowl, toss the onions with 4 teaspoons olive oil, 1/2 cup all-purpose flour, 2 tablespoons panko bread crumbs, and 1/2 teaspoon sea salt. Spread evenly on the baking sheets and bake for 25 to 35 minutes, tossing every 10 minutes (rotating the pans in the oven as necessary), until lightly browned and crispy. Store at room temperature until you're ready to assemble the casserole.
Vegan option: Omit the cheese and add a few extra pinches of salt to the mushroom sauce.