Vegan Green Bean Casserole (Dairy-Free) – Cozy, Creamy, and Crowd-Pleasing

This vegan green bean casserole brings all the comfort of the classic, minus the dairy. It’s creamy, savory, and topped with crispy onions that stay crunchy even after baking. The sauce is rich and silky, made from mushrooms, garlic, and a touch of miso for depth.

Whether you’re cooking for the holidays or just a cozy weeknight, this version feels familiar and tastes amazing. No complicated steps, no fake flavors—just real ingredients that come together beautifully.

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Vegan Green Bean Casserole (Dairy-Free) - Cozy, Creamy, and Crowd-Pleasing

Prep Time 15 minutes minutes

Cook Time 45 minutes minutes

Total Time 1 hour hour

Servings 8 servings

Ingredients

• Green beans: 1.5 to 2 pounds fresh (trimmed and halved), or two 12-ounce bags frozen, or four 14.5-ounce cans (drained)
• Olive oil or vegan butter: 3 tablespoons
• Yellow onion: 1 small, finely chopped
• Garlic: 3 cloves, minced
• Cremini or button mushrooms: 12 ounces, sliced
• All-purpose flour: 3 tablespoons (use gluten-free blend if needed)
• Vegetable broth: 1.5 cups, low-sodium
• Unsweetened non-dairy milk: 1 cup (oat, almond, or soy)
• White miso paste: 1 teaspoon (optional, for umami)
• Tamari or soy sauce: 1 tablespoon
• Ground black pepper: 1/2 teaspoon
• Kosher salt: To taste
• Onion powder: 1/2 teaspoon
• Nutmeg: Pinch (optional, but great)
• Lemon juice: 2 teaspoons (brightens the sauce)
• Crispy fried onions: 1.5 to 2 cups (store-bought, dairy-free)

Instructions

• Heat the oven: Preheat to 375°F (190°C). Grease a 9x13-inch baking dish or a similar casserole dish.
• Prep the green beans: If using fresh, bring a large pot of salted water to a boil. Blanch beans for 4–5 minutes until bright green and crisp-tender, then drain and shock in ice water.Pat dry. If using frozen, thaw and pat dry. If using canned, drain well and pat dry.
• Sauté the aromatics: In a large skillet, warm the olive oil or vegan butter over medium heat.Add chopped onion and cook 3–4 minutes until softened. Stir in garlic and cook 30 seconds until fragrant.
• Cook the mushrooms: Add sliced mushrooms with a pinch of salt. Cook 6–8 minutes, stirring occasionally, until they release their moisture and start to brown.Don’t rush this step—browning builds flavor.
• Build the roux: Sprinkle flour over the mushrooms and stir for 1 minute to coat and cook off the raw taste.
• Add liquids: Slowly whisk in the vegetable broth, then the non-dairy milk, stirring constantly to avoid lumps. Bring to a gentle simmer.
• Season the sauce: Stir in tamari/soy sauce, miso (if using), onion powder, pepper, and a pinch of nutmeg. Simmer 3–5 minutes until the sauce thickens to a creamy, gravy-like consistency.Taste and add salt as needed. Finish with lemon juice for brightness.
• Combine: Add the green beans to the skillet and toss to coat evenly. If your skillet isn’t large enough, mix everything in a big bowl.
• Assemble: Transfer to the baking dish.Smooth the top. Bake uncovered for 15–18 minutes until bubbling around the edges.
• Add the crunch: Remove from the oven, sprinkle the crispy fried onions evenly over the top, and return to the oven for 8–10 minutes until the onions are golden and crisp.
• Rest and serve: Let the casserole sit for 5–10 minutes before serving so the sauce settles and thickens slightly.

What Makes This Recipe So Good

• Classic comfort, dairy-free: You get that nostalgic creamy texture with zero cream or butter. The mushroom sauce does all the heavy lifting.
• Big flavor, simple method: Fresh mushrooms, garlic, and a splash of tamari or soy sauce add umami without fuss.
• Crispy topping that stays crisp: Bake uncovered and add the fried onions at the end so they keep their crunch.
• Make-ahead friendly: Assemble the casserole a day ahead and bake just before serving.
• Flexible: Works with fresh, frozen, or canned green beans.

  Choose what’s easiest.

Shopping List

• Green beans: 1.5 to 2 pounds fresh (trimmed and halved), or two 12-ounce bags frozen, or four 14.5-ounce cans (drained)
• Olive oil or vegan butter: 3 tablespoons
• Yellow onion: 1 small, finely chopped
• Garlic: 3 cloves, minced
• Cremini or button mushrooms: 12 ounces, sliced
• All-purpose flour: 3 tablespoons (use gluten-free blend if needed)
• Vegetable broth: 1.5 cups, low-sodium
• Unsweetened non-dairy milk: 1 cup (oat, almond, or soy)
• White miso paste: 1 teaspoon (optional, for umami)
• Tamari or soy sauce: 1 tablespoon
• Ground black pepper: 1/2 teaspoon
• Kosher salt: To taste
• Onion powder: 1/2 teaspoon
• Nutmeg: Pinch (optional, but great)
• Lemon juice: 2 teaspoons (brightens the sauce)
• Crispy fried onions: 1.5 to 2 cups (store-bought, dairy-free)

Step-by-Step Instructions

1. Heat the oven: Preheat to 375°F (190°C). Grease a 9×13-inch baking dish or a similar casserole dish.
2. Prep the green beans: If using fresh, bring a large pot of salted water to a boil. Blanch beans for 4–5 minutes until bright green and crisp-tender, then drain and shock in ice water.

   Pat dry. If using frozen, thaw and pat dry. If using canned, drain well and pat dry.

3. Sauté the aromatics: In a large skillet, warm the olive oil or vegan butter over medium heat.

   Add chopped onion and cook 3–4 minutes until softened. Stir in garlic and cook 30 seconds until fragrant.

4. Cook the mushrooms: Add sliced mushrooms with a pinch of salt. Cook 6–8 minutes, stirring occasionally, until they release their moisture and start to brown.

   Don’t rush this step—browning builds flavor.

5. Build the roux: Sprinkle flour over the mushrooms and stir for 1 minute to coat and cook off the raw taste.
6. Add liquids: Slowly whisk in the vegetable broth, then the non-dairy milk, stirring constantly to avoid lumps. Bring to a gentle simmer.
7. Season the sauce: Stir in tamari/soy sauce, miso (if using), onion powder, pepper, and a pinch of nutmeg. Simmer 3–5 minutes until the sauce thickens to a creamy, gravy-like consistency.

   Taste and add salt as needed. Finish with lemon juice for brightness.

8. Combine: Add the green beans to the skillet and toss to coat evenly. If your skillet isn’t large enough, mix everything in a big bowl.
9. Assemble: Transfer to the baking dish.

   Smooth the top. Bake uncovered for 15–18 minutes until bubbling around the edges.

10. Add the crunch: Remove from the oven, sprinkle the crispy fried onions evenly over the top, and return to the oven for 8–10 minutes until the onions are golden and crisp.
11. Rest and serve: Let the casserole sit for 5–10 minutes before serving so the sauce settles and thickens slightly.

Storage Instructions

• Refrigerator: Store leftovers in an airtight container for up to 4 days. Reheat in the oven at 350°F until warmed through.

  Add fresh fried onions on top to restore crunch.

• Freezer: Freeze the casserole without the fried onion topping for up to 2 months. Thaw overnight in the fridge, reheat, then add onions and bake 5–8 minutes to crisp.
• Make-ahead: Assemble the casserole (through step 9) up to 24 hours in advance. Cover and refrigerate.

  Bake, then add fried onions at the end.

Health Benefits

• Fiber-rich: Green beans provide fiber for digestive health and steady energy.
• Vitamins and minerals: You get vitamins A, C, K, and folate, plus potassium and iron from the beans and mushrooms.
• Dairy-free comfort: Using non-dairy milk and olive oil reduces saturated fat compared to traditional versions.
• Umami without excess sodium: Miso and mushrooms add depth so you can use less salt.

What Not to Do

• Don’t skip drying the beans: Excess water makes the sauce thin and the topping soggy.
• Don’t overcrowd the mushrooms: If the pan is too full, they steam and won’t brown. Cook in batches if needed.
• Don’t add fried onions too early: They’ll lose their crunch if baked the entire time.
• Don’t boil the sauce hard: Gentle simmering keeps it creamy and prevents curdling in some plant milks.
• Don’t forget to taste: Seasoning at the end makes a big difference. Adjust salt, pepper, and acidity.

Variations You Can Try

• Gluten-free: Use a 1:1 gluten-free flour blend and certified gluten-free fried onions.

  Tamari instead of soy sauce.

• Garlic-thyme twist: Add 1 teaspoon fresh thyme leaves with the mushrooms and an extra clove of garlic.
• Smoky version: Stir in 1/2 teaspoon smoked paprika and a dash of liquid smoke.
• Crunch upgrade: Mix crushed almonds or toasted panko with the fried onions for extra texture.
• Extra-creamy: Swap 1/3 cup of the non-dairy milk for full-fat canned coconut milk. The coconut flavor won’t dominate once seasoned.
• Spicy kick: Add a pinch of red pepper flakes to the sauce.
• Mushroom medley: Use a mix of cremini, shiitake, and oyster mushrooms for deeper flavor.

FAQ

Can I use canned cream of mushroom soup?

Many canned soups contain dairy, so check labels carefully. This homemade sauce is quick, dairy-free, and tastes fresher, so it’s worth the few extra minutes.

Which plant milk works best?

Unsweetened oat or soy milk gives the creamiest results.

Avoid vanilla or sweetened varieties. Almond milk works too but is a bit thinner.

Can I make this on the stovetop only?

You can skip baking by simmering the beans in the sauce until hot and tender, then topping with fried onions just before serving. The oven does help meld flavors and crisp the topping, though.

How do I keep the onions crispy for leftovers?

Store leftover fried onions separately if possible, and add fresh ones when reheating.

A quick bake or air-fry revives their crunch.

What if my sauce is too thin?

Simmer a few extra minutes to reduce. Or whisk 2 teaspoons flour with a splash of non-dairy milk, then stir into the sauce and simmer briefly.

What if my sauce is too thick?

Whisk in a few tablespoons of warm broth or plant milk until it loosens to your liking.

Can I prepare it two days ahead?

Yes, cook the sauce and beans, assemble in the dish, and refrigerate tightly covered for up to 48 hours. Bake just before serving and add fried onions at the end.

In Conclusion

This vegan green bean casserole delivers all the cozy, creamy satisfaction of the original without dairy.

The mushroom sauce is rich but simple, the beans stay tender, and the onion topping brings the perfect crunch. It’s reliable enough for holiday tables and easy enough for weeknights. Make it once, and it will become your go-to comfort side.