This vegan green bean casserole has become a staple in my kitchen, especially during the holidays and family gatherings. I love how it brings everyone to the table, whether they follow a plant-based diet or not. The aroma of sautéed mushrooms and onions fills the kitchen, and the crispy topping always draws compliments.

What makes this casserole special for me is the homemade mushroom sauce. It’s creamy without being heavy and coats the green beans perfectly. The texture is just right: tender beans, a rich sauce, and a golden, crunchy finish.

I usually serve this as a side dish for Thanksgiving or Sunday dinners, but it also works well as a main with a hearty salad. It’s comforting, familiar, and always disappears quickly.

The process is straightforward, and the results are worth it. You get all the classic flavors, but in a lighter, dairy-free version that everyone can enjoy.

Quick Facts

Why You’ll Love It

This vegan green bean casserole offers classic comfort with a plant-based twist. It’s creamy, flavorful, and crowd-pleasing, making it perfect for gatherings or weeknight dinners. The homemade sauce and crispy topping make it stand out from store-bought versions.

• Classic holiday side, now fully vegan
• Homemade mushroom sauce—no canned soup
• Crispy, golden onion topping
• Simple, everyday ingredients
• Great for meal prep and leftovers

Ingredients

This casserole uses fresh green beans, mushrooms, and a handful of pantry staples to create a creamy, satisfying dish. The crispy topping is made from store-bought or homemade fried onions. If you prefer, you can swap in gluten-free flour or onions for dietary needs.

• 1 1/2 pounds fresh green beans, trimmed and cut in half
• 2 tablespoons olive oil
• 1 medium yellow onion, finely chopped
• 3 cloves garlic, minced
• 8 ounces cremini or white mushrooms, sliced
• 1/4 cup all-purpose flour
• 1 1/2 cups unsweetened non-dairy milk (such as almond or soy)
• 1 cup low-sodium vegetable broth
• 1 tablespoon soy sauce or tamari
• 1/2 teaspoon dried thyme
• 1/2 teaspoon salt, plus more to taste
• 1/4 teaspoon black pepper
• 1 1/2 cups crispy fried onions (store-bought or homemade)

Step-by-Step Instructions

The steps are simple: blanch the beans, make the mushroom sauce, combine, and bake. Give yourself time for the sauce to thicken and the casserole to bake to golden perfection. Here’s how I do it:

1. Preheat your oven to 375°F (190°C).
2. Bring a large pot of salted water to a boil. Add green beans and cook for 4–5 minutes, until just tender and bright green. Drain and rinse under cold water to stop cooking.
3. In a large skillet, heat olive oil over medium heat. Add onion and cook for 3–4 minutes until soft.
4. Add garlic and mushrooms. Cook for 6–8 minutes, stirring, until mushrooms are browned and their liquid has evaporated.
5. Sprinkle flour over the vegetables and stir to coat. Cook for 1 minute.
6. Slowly whisk in the non-dairy milk and vegetable broth. Add soy sauce, thyme, salt, and pepper.
7. Bring to a simmer, stirring often, until sauce thickens (about 5–7 minutes). Taste and adjust seasoning.
8. Add the blanched green beans to the skillet and stir to coat.
9. Transfer mixture to a 9×13-inch baking dish. Top evenly with crispy fried onions.
10. Bake for 20–25 minutes, until bubbly and the topping is golden brown.
11. Let cool for 5–10 minutes before serving.

Chef Tips

A few simple tricks can help you get the best results. Here’s what I’ve learned from making this casserole many times:

• Use fresh green beans for best texture.
• Don’t overcook the beans—they should stay slightly crisp.
• Let the sauce thicken fully before combining with beans.
• If using homemade fried onions, make them ahead.
• Add extra mushrooms for a meatier flavor.
• Taste and adjust seasoning before baking.

Substitutions

This recipe is flexible and can be adapted for different dietary needs or what you have on hand. Here are some easy swaps I’ve tried:

• Use gluten-free flour and onions for a gluten-free version.
• Swap soy sauce for tamari to keep it gluten-free.
• Use oat, soy, or almond milk—just make sure it’s unsweetened.
• Substitute shallots for onion for a milder flavor.
• Try baby bella or portobello mushrooms for deeper flavor.
• Use frozen green beans in a pinch (thaw and drain first).

Storage & Reheating

This casserole stores well and reheats nicely, making it great for leftovers or meal prep. Here’s how I keep it fresh and tasty:

• Cool completely before storing.
• Refrigerate in an airtight container for up to 4 days.
• Reheat in the oven at 350°F until warmed through and topping is crisp.
• Microwave individual portions, but topping may soften.
• Freeze (without the onion topping) for up to 2 months; add onions before baking.

Perfect Pairings

This casserole pairs well with a range of mains and sides. I like to serve it as part of a holiday spread or with simple weeknight dishes. Here are some ideas:

• Roasted nut loaf or vegan meatloaf
• Crispy roasted potatoes
• Dry white wine (like Sauvignon Blanc)
• Simple green salad with lemon vinaigrette

FAQs

If you’re making this for the first time, you might have a few questions. Here are the answers to some common ones I’ve received:

Nutritional Note

Nutrition will vary by ingredients, but each serving is approximately 180–220 calories, with moderate fiber and no cholesterol.