Creamy Green Bean Casserole (from Scratch!)
This homemade green bean casserole tastes just like the cozy classic you remembe but even better. Made from scratch with tender green beans, a creamy mushroom sauce, and perfectly crispy onions baked on top, it’s the kind of side dish that steals the spotlight. Whether it’s Thanksgiving, Sunday dinner, or just a chilly evening at home, this casserole brings pure comfort to the table.
Ingredients
For the beans + sauce:
- 1 lb (450 g) fresh green beans trimmed and halved
- 3 tbsp unsalted butter
- 1 small yellow onion finely chopped
- 2 cloves garlic minced
- 8 oz (225 g) cremini mushrooms finely chopped
- 2 tbsp all-purpose flour
- 1½ cups whole milk (or half-and-half for extra richness)
- 1 cup chicken broth (or vegetable broth)
- ¼ cup grated Parmesan cheese
- ½ tsp black pepper
- ½ tsp salt plus more to taste
- ¼ tsp smoked paprika (optional but adds depth)
- 4 strips bacon, cooked crisp and crumbled (optional but recommended)
For the topping:
- 1 large onion thinly sliced into rings
- ½ cup all-purpose flour
- ½ cup buttermilk (or regular milk)
- 1 tsp salt
- 1 cup panko breadcrumbs (for crunch)
- oil for frying (canola or vegetable)
Instructions
Blanch the beans:
- Bring a large pot of salted water to a boil. Add green beans and cook for 4–5 minutes until tender-crisp. Drain and plunge into ice water to stop the cooking. Set aside.
Make the creamy mushroom base:
- In a large skillet, melt butter over medium heat. Add onion and cook until soft, about 3 minutes. Stir in garlic and mushrooms; sauté until mushrooms release their moisture and start browning about 7–8 minutes.
Thicken the sauce:
- Sprinkle flour over the mushroom mixture and stir to coat. Cook for 1 minute, then slowly pour in the milk and broth while whisking to avoid lumps. Let it simmer until thickened (around 5 minutes). Stir in Parmesan, pepper, salt, and smoked paprika. Add the crumbled bacon if using.
Combine beans and sauce:
- Toss the blanched green beans into the mushroom sauce and stir until evenly coated.
Make the crispy onion topping:
- Soak the onion rings in buttermilk for 10 minutes. Toss in flour mixed with salt and panko, then fry in hot oil (about 350°F / 175°C) until golden brown. Drain on paper towels. (Or air-fry at 375°F for 8–10 minutes until crisp.)
Assemble and bake:
- Pour the green bean mixture into a baking dish (the black oval one you showed is perfect). Top with crispy onions. Bake at 375°F (190°C) for 20–25 minutes, until bubbling and golden.
Notes
- Don’t overcook the beans before baking that’s how you keep that bright green pop.
- Use cremini mushrooms instead of button; they give that deep, umami flavor you see in your photo.
- Crispy onions right before serving that’s how you keep them from softening.
- A sprinkle of fresh thyme over the top after baking adds that warm, herby aroma like in the picture.