Green Bean Casserole from Scratch – Creamy with Crispy Onions
This Green Bean Casserole from scratch features fresh green beans in a creamy mushroom sauce, topped with homemade crispy fried onions.
This Green Bean Casserole from scratch is the make-ahead side dish your holiday table deserves. Fresh green beans are tossed in a creamy mushroom sauce, crowned with crunchy homemade fried onions. It tastes like a classic, but every bite is brighter and better than anything from a can.
Why You'll Love This Green Bean Casserole
- Fresh beans and mushrooms give it a crisp texture and deep flavor.
- The creamy sauce uses broth and a splash of lemon for a light, bright finish.
- Crispy fried onions are made from scratch and stay crunchy on top.
- You can assemble it ahead and bake when you are ready.
Ingredient Notes
Fresh green beans are the backbone of this casserole. Look for beans that snap easily and have a bright green color. Cremini mushrooms add a meaty, earthy flavor; white button mushrooms work just as well. For the sauce, use low-sodium chicken or vegetable broth so you can control the salt. Heavy cream makes it silky, but you can substitute half-and-half for a lighter finish. Buttermilk helps the onion coating crisp up; if you do not have it, mix 1 cup of milk with 1 tablespoon of lemon juice and wait five minutes. The lemon juice in the sauce brightens the whole dish without being noticeable.
How to Make Green Bean Casserole
Start by soaking thinly sliced onions in buttermilk while you prep the beans. Then cook the green beans briefly in salted water until bright and just tender, and cool them in an ice bath. Fry the coated onions in shallow oil until golden, then set them aside. For the sauce, sauté sliced mushrooms and minced shallots in butter, stir in flour, and slowly whisk in broth and cream. Simmer until the sauce is thick enough to coat the back of a spoon, then add lemon juice and season generously. Fold the beans into the sauce, transfer to a baking dish, and bake until bubbly. Add the fried onions on top for the last ten minutes so they stay crunchy.
Tips for the Best Green Bean Casserole
- Blanch the green beans until they are just crisp-tender; they will continue to cook in the oven.
- Dry the beans well after the ice bath so the sauce is not watered down.
- Keep an eye on the fried onions; they go from golden to burnt quickly.
- Make the sauce slightly thinner than you think, because it thickens as it bakes.
- Do not skip the lemon juice; it keeps the creamy sauce from feeling heavy.
Make Ahead and Storage
Assemble the casserole without the crispy onions up to two days in advance. Cover and refrigerate, then bake as directed. For a longer freeze, wrap the unbaked casserole tightly and freeze for up to one month; thaw it in the refrigerator overnight before baking. Store leftovers in an airtight container for up to three days. Reheat individual portions in the microwave or in a 350°F oven for about 10 minutes. Crispy onions are best the day they are made, but you can store them in a separate container for up to two days.
What to Serve With Green Bean Casserole
This Green Bean Casserole is the perfect side for roasted turkey, herb-roasted chicken, or a juicy beef roast. It also pairs well with mashed potatoes and dinner rolls for a full holiday spread. For a weeknight dinner, serve it alongside grilled chicken or a simple pan-seared chicken breast. Even a bowl of warm soup and a slice of crusty bread work when you want a comforting meal.
Ingredients
- 2 large yellow onions, thinly sliced into rings
- 1 cup buttermilk
- 1 cup all-purpose flour
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 2 cups vegetable oil, for frying
- 1 1/2 pounds fresh green beans, trimmed and halved
- 2 tablespoons unsalted butter
- 8 ounces cremini mushrooms, sliced
- 2 shallots, minced
- 3 tablespoons all-purpose flour
- 1 cup low-sodium chicken or vegetable broth
- 1 cup heavy cream
- 1 teaspoon lemon juice
- 1/2 teaspoon salt, plus more to taste
- 1/4 teaspoon black pepper
Instructions
Soak the onions
Toss the thinly sliced onions with buttermilk in a bowl and let sit for 15 minutes.
Fry the onions
Whisk the 1 cup flour with salt and pepper in a shallow dish. Dredge the onions in the flour, shaking off excess. Heat 1/2 inch of vegetable oil in a deep skillet to 350°F. Fry the onions in batches until golden, 2-3 minutes per batch. Drain on paper towels.
Blanch the green beans
Bring a pot of salted water to a boil. Add the green beans and cook until bright green and crisp-tender, about 4 minutes. Drain and transfer to a bowl of ice water to stop cooking. Dry thoroughly.
Make the sauce
Melt butter in a large skillet over medium heat. Add mushrooms and shallots and sauté until golden and softened, 5-6 minutes. Stir in the 3 tablespoons flour and cook for 1 minute. Slowly whisk in the broth and heavy cream, then simmer until thickened, about 3-4 minutes. Add lemon juice and season with salt and pepper.
Assemble the casserole
Preheat the oven to 375°F. Fold the green beans into the sauce and transfer the mixture to a 9x13-inch baking dish.
Bake and top
Bake for 20 minutes until bubbly. Top with the crispy onions and bake for 10 more minutes until the onions are golden and crisp. Let rest for 5 minutes before serving.
Notes
- Use a large pot for blanching so the beans cook evenly.
- For a vegetarian version, use vegetable broth instead of chicken broth.
- Store leftover crispy onions in a separate airtight container to keep them crisp for up to two days.
- If you want extra-crispy onions, double coat them by dipping back into the buttermilk and flour before frying.
Nutrition Facts
Frequently asked questions
Can I make Green Bean Casserole ahead of time?
Yes, assemble the casserole without the crispy onions up to two days ahead, cover, and refrigerate. When ready, bake as directed and add the onions for the last 10 minutes.
Can I use frozen green beans for Green Bean Casserole?
You can use thawed frozen green beans, but reduce the initial blanching time to 2 minutes. Frozen beans are softer, so expect a more tender texture.
How do I keep the crispy onions from getting soggy on Green Bean Casserole?
Add the crispy onions only during the last 10 minutes of baking. If you are reheating leftovers, keep the onions separate and add them after reheating.
What can I use instead of buttermilk for the crispy onions on Green Bean Casserole?
Mix 1 cup of milk with 1 tablespoon of lemon juice or white vinegar and let it sit for 5 minutes. This homemade buttermilk will tenderize the onions just as well.
Can I make Green Bean Casserole without heavy cream?
Use half-and-half or whole milk mixed with 2 tablespoons of melted butter to replace the heavy cream. The sauce will be lighter but still creamy.
How long does Green Bean Casserole take to cook?
The total time is about 55 minutes, including 20 minutes of prep. The casserole bakes for 30 minutes, with the crispy onions added during the final 10 minutes.
