This Southern Green Bean Casserole is creamy, cheesy, savory, and topped with plenty of crispy fried onions. It is the kind of warm side dish that fits right in at Sunday dinner, Thanksgiving, Christmas, or a simple family meal. The recipe is easy to follow, and the homemade creamy sauce gives it a rich Southern-style flavor.
Servings: 8
Prep Time: 15 minutes
Cook Time: 30 minutes
Total Time: 45 minutes
Why I Love This Recipe
Green bean casserole always makes me think of a table packed with comfort food. Someone brings the potatoes, someone has the rolls, and then this warm casserole comes out of the oven with that crispy onion topping everyone recognizes.
I like making the sauce from scratch instead of relying only on canned soup. It takes just a few extra minutes, but you get a creamy sauce with mushrooms, garlic, butter, and real cheese. It tastes rich without being complicated.
Here is what keeps this recipe on my list:
- Creamy inside: The homemade mushroom sauce coats every green bean.
- Crispy on top: Fried onions give you a great crunch in every serving.
- Lots of flavor: Garlic, mushrooms, cheddar, and Worcestershire sauce add savory flavor.
- Simple ingredients: Everything is easy to find at a regular grocery store.
- Great for gatherings: One casserole makes about 8 side-dish servings.
- Easy to prep early: You can assemble most of it ahead of time and bake it when needed.
What You’ll Need
- 2 pounds fresh green beans, trimmed and cut into 2-inch pieces
- 2 tablespoons unsalted butter
- 8 ounces cremini or white mushrooms, sliced
- 2 cloves garlic, minced
- 3 tablespoons all-purpose flour
- 1 1/2 cups whole milk
- 1 cup low-sodium chicken broth
- 1 teaspoon Worcestershire sauce
- 1 teaspoon kosher salt, plus extra for the boiling water
- 1/2 teaspoon black pepper
- 1 cup shredded sharp cheddar cheese
- 2 cups crispy fried onions, divided
Recipe and Instructions
Step 1: Blanch the Green Beans
Preheat the oven to 375°F (190°C).
Bring a large pot of water to a boil. Add a generous pinch of kosher salt. Add 2 pounds trimmed green beans cut into 2-inch pieces. Boil them for 4 minutes. They should turn bright green and become slightly tender but still have a little bite.
Drain the beans well in a colander. Let them sit while you make the sauce. Removing extra water helps keep the casserole from becoming watery.
Step 2: Cook the Mushrooms and Garlic
Place a large skillet over medium heat. Melt 2 tablespoons unsalted butter.
Add 8 ounces sliced cremini or white mushrooms. Cook for 5 to 6 minutes, stirring now and then, until the mushrooms soften and most of their liquid cooks away.
Add 2 cloves minced garlic. Stir and cook for 30 seconds, just until you can smell the garlic.
Step 3: Make the Creamy Sauce
Sprinkle 3 tablespoons all-purpose flour over the cooked mushrooms and garlic. Stir constantly for 1 minute. The flour will soak up the butter and coat the mushrooms.
Slowly pour in 1 1/2 cups whole milk and 1 cup low-sodium chicken broth, whisking as you pour so the sauce stays smooth.
Stir in 1 teaspoon Worcestershire sauce, 1 teaspoon kosher salt, and 1/2 teaspoon black pepper.
Cook over medium heat for 3 to 5 minutes, stirring often, until the sauce is thick enough to lightly coat the back of a spoon.
Step 4: Add the Cheese
Turn the heat to low. Add 1 cup shredded sharp cheddar cheese to the thickened mushroom sauce.
Stir for about 1 minute, until the cheese is fully melted and the sauce is smooth. Remove the skillet from the heat.
Step 5: Assemble the Casserole
Put the 2 pounds blanched and well-drained green beans into a round casserole dish.
Pour all of the warm cheddar mushroom sauce over the beans. Add 1 cup crispy fried onions and gently fold everything together until the beans are evenly coated.
Spread the mixture into an even layer.
Step 6: Bake the Casserole
Place the casserole in the 375°F (190°C) oven and bake uncovered for 20 minutes.
The sauce should be hot and bubbling around the edges.
Step 7: Add the Crispy Topping and Finish Baking
Carefully remove the casserole from the oven. Sprinkle the remaining 1 cup crispy fried onions evenly over the top.
Return it to the 375°F (190°C) oven for 5 to 10 minutes, until the onions are crisp and golden brown.
Let the casserole rest for 5 minutes before serving. This gives the creamy sauce time to settle.
Why This Recipe Works (Quick Science)
There are a few simple reasons this casserole comes out creamy instead of thin.
- Blanching helps the beans: A quick boil starts cooking the green beans while keeping their fresh color and texture.
- Cooking the mushrooms first matters: Mushrooms hold a lot of water. Cooking that water away helps prevent a runny casserole.
- Butter and flour thicken the sauce: Cooking flour in butter creates a base that thickens the milk and broth.
- Cheese adds body: Melted cheddar makes the sauce richer and helps it cling to the beans.
- The topping goes on late: Fried onions can burn if they bake too long. Adding the final layer near the end keeps them crunchy.
Pro Tips
- Drain the blanched green beans very well. Water left on them can thin the sauce.
- Shred cheddar from a block when possible. It usually melts more smoothly than bagged shredded cheese.
- Don’t overcook the beans during blanching. They keep cooking in the oven.
- Watch the fried onions during the final few minutes. They can go from golden to too dark quickly.
- Let the finished casserole rest for 5 minutes. It will be easier to scoop and serve.
Tools You’ll Need
- Large pot
- Colander
- Large skillet
- Wooden spoon
- Whisk
- Chef’s knife
- Cutting board
- Measuring cups
- Measuring spoons
- Large mixing spoon
- Round casserole dish
Substitutions and Variations
- Frozen green beans: Use 2 pounds thawed green beans. Drain them very well and skip blanching.
- Canned green beans: Use about 4 cans, 14.5 ounces each, drained very well. They will have a softer texture.
- Vegetable broth: Swap it for chicken broth to make the casserole meat-free. Check that your Worcestershire sauce is vegetarian too if needed.
- Monterey Jack: Use it instead of cheddar for a milder cheese flavor.
- Extra mushrooms: Add another 4 ounces if you want stronger mushroom flavor.
- Bacon: Add 1/2 cup cooked, crumbled bacon for a smoky variation.
- Spicy version: Add 1/4 teaspoon cayenne pepper to the sauce.
Make-Ahead Tips
You can blanch the beans and make the sauce up to 1 day ahead. Assemble the casserole with the first cup of fried onions, cover it, and refrigerate.
Keep the final 1 cup fried onions separate so they stay crisp.
When you are ready to cook, take the casserole out of the refrigerator while the oven heats. A cold casserole may need an extra 5 to 10 minutes of baking before you add the final onion topping.
Common Mistakes
- Watery casserole: This often happens when the green beans or mushrooms contain too much water. Drain the beans well and cook the mushrooms until their released liquid is mostly gone.
- Lumpy sauce: Add the milk and broth slowly while whisking.
- Mushy beans: Don’t boil fresh beans longer than about 4 minutes before baking.
- Burned fried onions: Add the final cup only during the last 5 to 10 minutes.
- Sauce that is too thick: If your sauce becomes very thick in the skillet, stir in a small splash of milk before assembling the casserole.
What to Serve With Southern Green Bean Casserole
This rich casserole works especially well beside simple roasted or baked main dishes. Try it with:
- Roast turkey
- Baked ham
- Roast chicken
- Pork chops
- Meatloaf
- Mashed potatoes
- Sweet potato casserole
- Cornbread
- Dinner rolls
- Cranberry sauce
For a holiday meal, turkey, mashed potatoes, cranberry sauce, rolls, and this casserole make a classic combination.
Macros Information
Approximate nutrition per serving, based on 8 servings:
- Calories: 310
- Protein: 10 g
- Carbohydrates: 28 g
- Fat: 19 g
- Fiber: 4 g
- Sugar: 7 g
These numbers are estimates. The exact macros will change depending on the brands of cheese, broth, milk, and fried onions you use.
Leftovers and Storage
Let leftovers cool, then place them in an airtight container or cover the casserole dish well. Refrigerate for up to 4 days.
For the best texture, reheat leftovers in a 350°F oven for about 15 minutes, or until hot. You can sprinkle a few fresh fried onions on top before reheating to bring back some crunch.
For a quick serving, microwave it until hot. The onions will be softer, but the casserole will still taste good.
Freezing is possible, but it is not my first choice. The creamy sauce can change texture after thawing, and the fried onions lose their crunch.
FAQ
Q: Can I use canned green beans?
A: Yes. Use about four 14.5-ounce cans and drain them very well. You do not need to blanch them. Canned beans will give you a softer casserole.
Q: Can I use frozen green beans?
A: Yes. Thaw 2 pounds of frozen green beans and drain away as much moisture as possible before assembling the casserole.
Q: Can I make this without mushrooms?
A: Yes. Leave out the mushrooms and cook the garlic briefly in the butter before adding the flour. The casserole will have a different flavor but will still have a creamy sauce.
Q: Why is my green bean casserole watery?
A: Extra moisture is usually the cause. Drain the green beans well, and let the mushrooms cook until most of the liquid they release has evaporated.
Q: Can I make it the night before?
A: Yes. Assemble it without the final cup of fried onions, cover it, and refrigerate overnight. Add the last cup of onions near the end of baking.
Q: How do I know when it is done?
A: The sauce should be bubbling around the edges, the casserole should be hot in the center, and the fried onions on top should be crisp and golden.
Final Thoughts
Southern Green Bean Casserole is simple comfort food that earns its place on the dinner table. You get tender green beans, a rich homemade mushroom and cheddar sauce, and those crunchy golden onions on top.
Make it for a holiday feast, Sunday dinner, or whenever you want a warm side dish that goes with almost everything. Once you’ve tried it, leave a comment about how yours turned out, any changes you made, or any questions you have.