Green Bean Casserole with Crispy Onions
This green bean casserole with crispy onions is the creamy, crunchy holiday classic — tender green beans in a savory homemade mushroom sauce, baked until bubbly and crowned with golden crispy fried onions. Ready in about 45 minutes, it’s the side dish everyone reaches for first.
Why You’ll Love It
- Holiday classic. Guests expect it on the Thanksgiving table.
- Creamy + crunchy. Silky homemade sauce with a shattering onion topping.
- From scratch, but easy. The homemade sauce beats canned and takes just minutes more.
- Make-ahead friendly. Assemble the day before and bake when ready.
- Feeds a crowd. Serves 10 — perfect for gatherings.
Why It Works
Blanched beans stay bright and snappy instead of dull and soggy. Real cremini mushrooms sautéed in butter with garlic and thyme build deep, savory flavor that canned soup can’t match. The crispy onions go in two layers — half stirred into the casserole and half on top — for maximum crunch in every bite.
Green Bean Casserole with Crispy Onions
Ingredients
Method
- Blanch the beans: boil for 3 minutes, transfer to an ice bath, then drain and pat dry.
- Melt the butter in a large oven-safe skillet over medium-high heat. Add the mushrooms and cook, stirring occasionally, until browned, 6 to 8 minutes. Add the garlic and thyme and cook for 1 minute more.
- Stir in the flour and cook for 1 minute. Whisk in the broth, cream, and soy sauce and simmer, whisking, until thickened.
- Stir in the blanched green beans and 1 1/2 cups of the crispy fried onions. Season with salt and black pepper to taste.
- Transfer to a baking dish if needed. Bake at 375°F (190°C) for 20 minutes, until hot and bubbly.
- Top with the remaining 1 1/2 cups crispy fried onions and bake 5 minutes more, until golden.
- Let rest 5 minutes before serving.
Key Ingredients
- Green beans: 2 lbs fresh, trimmed. Choose firm, bright-green beans.
- Mushrooms: 12 oz cremini, sliced, for a deep savory base.
- Butter: 4 tablespoons, for sautéing and the roux.
- Flour: 1/4 cup, to thicken the sauce.
- Broth: 1 1/2 cups low-sodium chicken or vegetable broth.
- Cream: 1 cup heavy cream, for richness.
- Soy sauce: 1 tablespoon, for umami depth.
- Crispy onions: 3 cups, divided — half stirred in, half on top.
Tips for the Best Green Bean Casserole
Blanch the beans for 3 minutes and shock them in an ice bath — don’t skip this step; it’s what keeps them bright green and crisp-tender. Add the crispy onions in two layers, and bake the final 5 minutes uncovered so the topping turns deeply golden.
Variations
- Bacon: Stir in crumbled cooked bacon with the beans.
- Cheesy: Fold a cup of shredded Gruyère into the sauce.
- Vegan: Use plant-based butter and cream with vegetable broth.
What to Serve With
Serve it alongside roast turkey, glazed ham, or creamy mashed potatoes — it’s a natural fit for any holiday spread.
Storage
To store: Refrigerate leftovers in an airtight container for up to 4 days. To reheat: Warm at 350°F (175°C) for about 20 minutes, then add a fresh handful of crispy onions on top to bring back the crunch.
FAQs
Can I use fresh or frozen green beans?
Fresh is best, but frozen works too — thaw them first and skip the blanching step.
Can I make it ahead?
Yes. Assemble the casserole without the topping, refrigerate overnight, then add the crispy onions and bake as directed.
Why is my casserole soggy?
The beans were likely overcooked or there was too much liquid. Blanch briefly and simmer the sauce until nicely thickened.
