This Southern Green Bean Casserole is everything I crave in a cozy holiday side: tender-crisp beans, a rich from-scratch mushroom cream sauce, and a golden, ultra-crispy onion topping. It tastes like childhood gatherings, but with fresher flavors and a just-right creamy finish.
Why You’ll Love This Southern Green Bean Casserole
- From-scratch flavor without canned soup, ready for any holiday table.
- Balanced texture: crisp-tender beans, creamy sauce, crunchy topping.
- Make-ahead friendly, so the big day feels calm and organized.
- Easy to customize for gluten-free, dairy-free, or extra-cheesy lovers.
- Classic Southern comfort with fresher, brighter ingredients.
Southern Green Bean Casserole Ingredients & Substitutions
For the casserole
- 1.5 lb fresh green beans, trimmed and halved (sub 2 cans cut green beans, drained well, or 24 oz frozen, thawed and patted dry)
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 12 oz cremini or button mushrooms, finely chopped
- 1 small yellow onion, finely diced
- 3 garlic cloves, minced
- 1/4 cup all-purpose flour (sub gluten-free all-purpose blend)
- 1 cup low-sodium chicken or vegetable broth
- 1 cup whole milk or half-and-half
- 1/2 cup sour cream (sub Greek yogurt)
- 1 tsp Worcestershire sauce
- 1 tsp soy sauce or coconut aminos
- 1 tsp fresh thyme leaves or 1/2 tsp dried
- 1/4 tsp grated nutmeg, optional
- 3/4 tsp kosher salt, plus more to taste
- 1/2 tsp black pepper
- 1/2 cup grated Parmesan, divided
- 1 cup shredded sharp cheddar, optional but very Southern
For the crispy topping
- 1 cup crispy fried onions, store-bought or homemade
- 1/2 cup panko breadcrumbs (sub gluten-free panko)
- 2 tbsp melted butter
- 2 tbsp grated Parmesan
Notes: Fresh beans give the best snap. If using canned, reduce salt and skip blanching. For dairy-free, use olive oil, plant milk, and a dairy-free sour cream and cheese or simply omit the cheese.
Step-by-Step Instructions to Make Southern Green Bean Casserole
1. Preheat and Prepare the Dish
Heat the oven to 350°F. Lightly grease a 9×13 inch baking dish and set aside.
2. Blanch the Green Beans
Bring a large pot of salted water to a boil. Add the green beans and cook 4 to 5 minutes until crisp-tender and bright green. Transfer to an ice bath to stop the cooking, then drain and pat very dry. If using canned or thawed frozen beans, skip blanching and simply pat dry.
3. Brown the Mushrooms and Aromatics
In a large skillet, melt the butter with the olive oil over medium-high heat. Add mushrooms and cook, stirring occasionally, until deeply browned and most moisture evaporates, 6 to 8 minutes. Stir in the diced onion and cook 3 to 4 minutes until softened. Add garlic and cook 30 seconds until fragrant.
4. Build the Creamy Sauce
Sprinkle flour over the mushroom mixture and cook 1 minute, stirring. Whisk in broth, then milk, and bring to a gentle simmer. Stir in Worcestershire, soy sauce, thyme, nutmeg, salt, and pepper. Simmer 2 to 3 minutes until thick and silky. Off the heat, stir in sour cream, 1/4 cup Parmesan, and cheddar if using. Taste and adjust seasoning.
5. Combine and Assemble
Fold the green beans into the sauce until evenly coated. Transfer to the prepared baking dish and smooth the top.
6. Mix the Crunchy Topping
In a bowl, combine crispy fried onions, panko, melted butter, and remaining 2 tbsp Parmesan. Sprinkle evenly over the casserole. For a classic vibe, you can use just fried onions.
7. Bake to Bubbly Perfection
Bake 25 to 30 minutes until bubbling at the edges and the topping is golden and crisp. Let rest 10 minutes before serving so the sauce sets.
Tips for Success
- Dry the beans well so the sauce stays thick and luscious.
- Brown the mushrooms deeply for rich, savory flavor.
- Season as you go. Taste the sauce before adding beans and adjust salt.
- Use half-and-half for extra richness, or whole milk for a lighter feel.
- Keep the topping crisp by adding it right before baking.
Variations of Southern Green Bean Casserole
- Bacon and Cheddar: Stir in 4 slices cooked, crumbled bacon and use the cheddar.
- Spicy Cajun: Add 1 tsp Cajun seasoning to the sauce and a pinch of cayenne.
- Garlic-Parmesan: Skip cheddar and increase Parmesan to 3/4 cup.
- Gluten-Free: Use GF flour and panko. Check fried onions are GF.
- Dairy-Free: Use plant milk, dairy-free sour cream, and skip cheeses or use DF alternatives.
Serving Suggestions: What to Pair with Southern Green Bean Casserole
- Roast turkey, ham, or herb-roasted chicken.
- Mashed potatoes, cornbread dressing, or brown butter rice pilaf.
- Cranberry sauce for a bright, tart contrast.
- Simple green salad with lemon vinaigrette to refresh the palate.
Storage & Reheating Instructions
- Refrigerate: Cover and chill up to 4 days.
- Reheat: Bake at 350°F for 15 to 20 minutes until hot. Tent with foil if browning too quickly, uncover for the last few minutes to re-crisp.
- Microwave: Good for single portions, then finish 2 to 3 minutes in a toaster oven or air fryer to crisp the top.
- Freeze: Assemble without the topping and freeze up to 2 months. Thaw overnight, add topping, and bake.
Memories Made Around the Table
My aunt kept a warm dish of this casserole parked near the kitchen door, and we all stole spoonfuls before dinner. The crispy edges never stood a chance.
FAQs
Can I use canned cream of mushroom soup?
Yes. Use 2 cans and skip the flour, broth, milk, and sour cream. You may want to add a splash of milk to loosen and still include the Worcestershire, soy, thyme, and pepper for flavor.
Can I make this Southern Green Bean Casserole ahead?
Assemble the casserole without the topping up to 2 days ahead. Cover and refrigerate. Add the topping just before baking. You may need 5 to 10 extra minutes if baking from cold.
Do I have to use cheddar?
No. Cheddar adds Southern flair, but the casserole is excellent with just Parmesan or even cheese-free.
How do I keep the topping crunchy for leftovers?
Reheat uncovered in a hot oven or air fryer. If the topping softens, add a small handful of fresh panko and fried onions before reheating.
Final Thoughts
This Southern Green Bean Casserole brings classic comfort with brighter, fresher flavor. It is simple, reliable, and always the first empty dish on my holiday table.
Southern Green Bean Casserole (From-Scratch, Creamy)
Equipment
- 1 Large Pot
- 1 Large Skillet
- 1 9x13 inch baking dish lightly greased
- 1 Colander
- 1 Mixing Bowl
- 1 Whisk
Ingredients
For the casserole
- 1.5 lb fresh green beans trimmed and halved
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 12 oz cremini or button mushrooms finely chopped
- 1 small yellow onion finely diced
- 3 cloves garlic minced
- 0.25 cup all-purpose flour
- 1 cup low-sodium chicken or vegetable broth
- 1 cup whole milk or half-and-half
- 0.5 cup sour cream
- 1 tsp Worcestershire sauce
- 1 tsp soy sauce or coconut aminos
- 1 tsp fresh thyme leaves or 1/2 tsp dried
- 0.25 tsp grated nutmeg optional
- 0.75 tsp kosher salt plus more to taste
- 0.5 tsp black pepper
- 0.5 cup grated Parmesan divided
- 1 cup shredded sharp cheddar optional
For the crispy topping
- 1 cup crispy fried onions store-bought or homemade
- 0.5 cup panko breadcrumbs or gluten-free panko
- 2 tbsp unsalted butter melted
- 2 tbsp grated Parmesan
Instructions
Casserole
- Heat the oven to 350°F. Lightly grease a 9x13-inch baking dish and set aside.
- Bring a large pot of salted water to a boil. Add the green beans and cook 4 to 5 minutes until crisp-tender and bright green. Transfer to an ice bath to stop the cooking, then drain and pat very dry. If using canned or thawed frozen beans, skip blanching and simply pat dry.
- In a large skillet, melt the butter with the olive oil over medium-high heat. Add mushrooms and cook, stirring occasionally, until deeply browned and most moisture evaporates, 6 to 8 minutes. Stir in the diced onion and cook 3 to 4 minutes until softened. Add garlic and cook 30 seconds until fragrant.
- Sprinkle flour over the mushroom mixture and cook 1 minute, stirring. Whisk in broth, then milk, and bring to a gentle simmer. Stir in Worcestershire, soy sauce, thyme, nutmeg, salt, and pepper. Simmer 2 to 3 minutes until thick and silky. Off the heat, stir in sour cream, 1/4 cup Parmesan, and cheddar if using. Taste and adjust seasoning.
- Fold the green beans into the sauce until evenly coated. Transfer to the prepared baking dish and smooth the top.
Topping & Bake
- In a bowl, combine crispy fried onions, panko, melted butter, and remaining 2 tbsp Parmesan. Sprinkle evenly over the casserole. For a classic vibe, you can use just fried onions.
- Bake 25 to 30 minutes until bubbling at the edges and the topping is golden and crisp. Let rest 10 minutes before serving so the sauce sets.