This Best Southern Green Bean Casserole is creamy, savory, and irresistibly crunchy on top. I make it from scratch with fresh green beans, smoky bacon, and a rich mushroom sauce that tastes like home on the holidays.
It is the side dish that disappears first, so do yourself a favor and make a little extra. One bite and you’ll taste the love.
Why You’ll Love This Best Southern Green Bean Casserole
- From-scratch flavor with a simple, reliable method.
- Fresh green beans that stay tender-crisp, never soggy.
- Smoky bacon and browned mushrooms add real depth.
- Ultra creamy sauce with a golden, ultra crispy onion topping.
- Make-ahead friendly for stress-free holidays.
Best Southern Green Bean Casserole Ingredients & Substitutions
- Fresh green beans: 2 lb, trimmed and halved. Sub canned: 4 cans (14.5 oz each), well drained; reduce bake time slightly.
- Kosher salt: For blanching water and seasoning.
- Thick-cut bacon: 6 slices (about 6 oz), chopped. Sub country ham or turkey bacon.
- Unsalted butter: 4 tbsp for sautéing and roux. Sub olive oil or dairy-free butter.
- Cremini mushrooms: 12 oz, sliced. Sub button mushrooms or a mix with shiitakes.
- Yellow onion: 1 small, finely diced. Sub 2 shallots.
- Garlic: 3 cloves, minced.
- All-purpose flour: 1/4 cup to thicken. For gluten-free, use a 1:1 GF flour or 2 tbsp cornstarch slurry.
- Chicken broth: 1 1/4 cups. Sub vegetable broth.
- Half-and-half: 1 1/4 cups. Sub 3/4 cup milk + 1/2 cup cream, or full-fat coconut milk for dairy-free.
- Worcestershire sauce: 1 1/2 tsp. Sub 1 tsp soy sauce or tamari.
- Dijon mustard: 1 tsp for gentle tang and balance.
- Fresh thyme: 1 tsp chopped, or 1/2 tsp dried.
- Black pepper: 1/2 tsp; cayenne or hot sauce: pinch, optional.
- Parmesan: 1/3 cup grated, optional but delicious.
- Crispy fried onions: 2 cups. Use gluten-free if needed.
- Panko breadcrumbs: 1/2 cup for extra crunch. Sub crushed crackers or omit.
- Melted butter or olive oil: 1 tbsp to toss with topping.
Step-by-Step Instructions to Make Best Southern Green Bean Casserole
Preheat and Prep the Dish
Heat oven to 350 F. Grease a 9×13 inch or 3 quart baking dish.
Blanch the Green Beans
Bring a large pot of well salted water to a boil. Add green beans and cook 4 to 5 minutes until bright green and just tender. Transfer to an ice bath to stop cooking, then drain and pat very dry so the sauce stays silky.
Crisp the Bacon
In a large skillet over medium heat, cook bacon until crisp, 6 to 8 minutes. Transfer to a paper towel lined plate. Reserve 2 tbsp bacon drippings in the skillet.
Sauté Mushrooms and Aromatics
Add 2 tbsp butter to the skillet with the drippings. Add mushrooms and onion with a pinch of salt. Cook, stirring occasionally, until mushrooms are deeply browned and most liquid evaporates, 8 to 10 minutes. Stir in garlic and thyme for 30 seconds.
Build the Creamy Sauce
Melt remaining 2 tbsp butter in the pan. Sprinkle in flour and cook, stirring, 1 minute. Slowly whisk in broth, then half-and-half, whisking until smooth. Simmer 3 to 4 minutes until thick and glossy. Stir in Worcestershire, Dijon, black pepper, and cayenne if using. Taste and season with salt.
Combine and Assemble
Fold in blanched green beans, half the bacon, and Parmesan if using. Transfer mixture to the prepared baking dish and smooth the top.
Make the Crispy Topping
In a bowl, toss crispy fried onions with panko and melted butter or oil. This combo gives you shattering crunch without burning.
Bake to Bubbly Perfection
Bake the casserole without topping for 20 minutes until bubbling at the edges. Sprinkle on the onion-panko mixture and remaining bacon. Bake 10 to 15 minutes more until golden and crisp. Rest 10 minutes before serving.
Tips for Success
- Salt the blanching water like the sea to season the beans from within.
- Dry the beans well so the sauce clings instead of thinning out.
- Brown mushrooms until deeply golden for maximum savory flavor.
- Add the topping near the end of baking to keep it crunchy.
- Taste and adjust the sauce before combining. It should be well seasoned and slightly salty to account for the beans.
Variations of Best Southern Green Bean Casserole
- Extra Cheesy: Fold 1 cup shredded sharp cheddar into the sauce.
- Cajun Spice: Add 1 tsp Cajun seasoning and a few dashes of hot sauce.
- Country Ham: Swap bacon for diced country ham for a true Southern twist.
- Gluten-Free: Use GF flour or cornstarch slurry and gluten-free fried onions.
- Vegan: Use olive oil, vegetable broth, and unsweetened plant milk plus nutritional yeast. Skip bacon or use plant-based.
Serving Suggestions: What to Pair with Best Southern Green Bean Casserole
- Roast turkey, glazed ham, or herb roasted chicken.
- Buttermilk mashed potatoes and turkey gravy.
- Cornbread dressing or buttery dinner rolls.
- Bright cranberry relish or a simple green salad for balance.
Storage & Reheating Instructions
- Refrigerate: Cool completely, then cover and refrigerate up to 4 days.
- Reheat: Warm at 325 F, 15 to 20 minutes, until hot. Broil 1 to 2 minutes to re-crisp the topping if needed.
- Freeze: Best frozen without the topping for up to 2 months. Thaw in the fridge, reheat until bubbly, then add fresh topping and bake to crisp.
Memories Made Around the Table
My grandma kept a warm oven and a bigger heart. Every Thanksgiving, this casserole came out bubbling, and we all hovered with spoons. I still hear the clink of her serving dish and feel that first crunch of onions as the room went quiet for one blissful bite.
FAQs
Can I make this casserole ahead?
Yes. Assemble up to the bake step without the topping, cover, and refrigerate up to 2 days. Bake until hot and bubbly, then add the topping and finish until crisp.
Can I use canned soup instead of making the sauce?
If you are short on time, use 2 cans cream of mushroom plus 1/2 cup milk. Skip the roux. The from-scratch version has fresher flavor, but this works in a pinch.
Fresh vs canned green beans?
Fresh gives the best texture and color. If using canned, drain very well and reduce the initial bake by 5 to 8 minutes since they are already tender.
How do I keep the topping from getting soggy?
Add it near the end of baking and let the casserole rest briefly so steam dissipates. Re-crisp under the broiler for 30 to 60 seconds before serving.
What size pan should I use?
A 9×13 inch or 3 quart baking dish is ideal. For a smaller gathering, halve the recipe and use an 8×8 inch pan.
Final Thoughts
Comforting, creamy, and beautifully balanced, this Best Southern Green Bean Casserole is the side that brings everyone back for seconds. Make it once and it will become your holiday tradition too.
Best Southern Green Bean Casserole (From Scratch)
Equipment
- 1 Large Pot for blanching
- 1 Large Skillet
- 1 9x13 inch baking dish or 3-quart
- 1 Colander
- 1 Mixing Bowl for topping
- 1 Whisk
Ingredients
Casserole
- 2 lb fresh green beans trimmed and halved
- Kosher salt for blanching water and seasoning
- 6 slices thick-cut bacon about 6 oz, chopped
- 4 tbsp unsalted butter
- 12 oz cremini mushrooms sliced
- 1 small yellow onion finely diced
- 3 cloves garlic minced
- 1 tsp fresh thyme chopped
- 0.25 cup all-purpose flour
- 1.25 cups chicken broth
- 1.25 cups half-and-half
- 1.5 tsp Worcestershire sauce
- 1 tsp Dijon mustard
- 0.5 tsp black pepper
- 1 pinch cayenne pepper or hot sauce optional
- 0.33 cup Parmesan grated, optional
Topping
- 2 cups crispy fried onions
- 0.5 cup panko breadcrumbs
- 1 tbsp melted butter or olive oil for tossing
Instructions
Preheat and Prep the Dish
- Heat oven to 350 F. Grease a 9x13 inch or 3 quart baking dish.
Blanch the Green Beans
- Bring a large pot of well salted water to a boil. Add green beans and cook 4 to 5 minutes until bright green and just tender. Transfer to an ice bath to stop cooking, then drain and pat very dry so the sauce stays silky.
Crisp the Bacon
- In a large skillet over medium heat, cook bacon until crisp, 6 to 8 minutes. Transfer to a paper towel lined plate. Reserve 2 tbsp bacon drippings in the skillet.
Sauté Mushrooms and Aromatics
- Add 2 tbsp butter to the skillet with the drippings. Add mushrooms and onion with a pinch of salt. Cook, stirring occasionally, until mushrooms are deeply browned and most liquid evaporates, 8 to 10 minutes. Stir in garlic and thyme for 30 seconds.
Build the Creamy Sauce
- Melt remaining 2 tbsp butter in the pan. Sprinkle in flour and cook, stirring, 1 minute. Slowly whisk in broth, then half-and-half, whisking until smooth. Simmer 3 to 4 minutes until thick and glossy. Stir in Worcestershire, Dijon, black pepper, and cayenne if using. Taste and season with salt.
Combine and Assemble
- Fold in blanched green beans, half the bacon, and Parmesan if using. Transfer mixture to the prepared baking dish and smooth the top.
Make the Crispy Topping
- In a bowl, toss crispy fried onions with panko and melted butter or oil. This combo gives you shattering crunch without burning.
Bake to Bubbly Perfection
- Bake the casserole without topping for 20 minutes until bubbling at the edges. Sprinkle on the onion-panko mixture and remaining bacon. Bake 10 to 15 minutes more until golden and crisp. Rest 10 minutes before serving.