Vegetarian Green Bean Casserole

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By: Ashley Wilson | Published: November 2, 2025

45 degree close shot of vegetarian green bean casserole with creamy mushroom sauce and crispy onions

🥄 Cozy, Creamy, Crowd-Loving (No Meat Needed)

Some sides taste like a hug.
Vegetarian Green Bean Casserole with Creamy Mushroom Sauce is exactly that—bright, tender green beans folded into a velvety mushroom cream and finished with a golden, crackly crown. One scoop in and you get it: comfort, nostalgia, and big holiday energy—without the heaviness.

This is the kind of bowl that earns a permanent spot at the table.
Weeknight trial run? Perfect.
Thanksgiving, Friendsgiving, or the big December feast? Absolutely.
With simple steps and pantry-friendly ingredients, Vegetarian Green Bean Casserole with Creamy Mushroom Sauce brings lush texture and deep flavor that even the “Where’s the meat?” guests happily devour.


🥕 Ingredients (Fresh & Vegetarian)

  • 2 lb fresh green beans, trimmed and halved (or 4 cans cut green beans, very well drained)
  • 3 tbsp unsalted butter (or olive oil)
  • 1 small shallot (or ½ onion), finely chopped
  • 3 cloves garlic, minced
  • 10–12 oz cremini or button mushrooms, thinly sliced
  • 3 tbsp all-purpose flour (or 2½ tbsp cornstarch mixed with broth for a slurry)
  • 1½ cups low-sodium vegetable broth, warm
  • 1½ cups milk (whole or 2%) or unsweetened almond milk, warm
  • ½ tsp dried thyme (or 1 tsp fresh, chopped)
  • ½ tsp kosher salt, plus more to taste
  • ¼ tsp black or white pepper
  • Pinch of nutmeg (optional, lovely warmth)
  • ½ cup finely grated Parmesan (optional; skip for fully vegetarian if you avoid animal rennet—use rennet-free or a vegetarian hard cheese)
  • 2 to 2½ cups crispy fried onions (store-bought or homemade; choose vegetarian-friendly brand)
  • A few parsley leaves, chopped (to finish)

Little lift: zest a whisper of lemon into the pot at the end for a bright finish on your Vegetarian Green Bean Casserole with Creamy Mushroom Sauce.


🍳 How to Make It

  1. Blanch the beans (fresh option).
    Big pot of salted water to a boil.
    Add beans; cook 4–5 minutes until bright and crisp-tender.
    Drain; plunge into ice water; drain again and pat dry.
    This keeps your Vegetarian Green Bean Casserole with Creamy Mushroom Sauce silky, not watery.
  2. Build the base.
    In a wide skillet or Dutch oven, melt butter over medium.
    Add shallot + pinch of salt; cook until soft and glossy.
    Stir in garlic for 30 seconds.
  3. Brown the mushrooms.
    Add mushrooms; cook until they release liquid and then lightly brown.
    Those toasty edges are where the magic happens for Vegetarian Green Bean Casserole with Creamy Mushroom Sauce.
  4. Make the creamy sauce.
    • Flour route: Sprinkle flour over mushrooms; cook 60–90 seconds, stirring.
    • Cornstarch route: Whisk cornstarch into warm broth to make a slurry.
      Slowly whisk in warm vegetable broth (or slurry), then warm milk.
      Simmer 3–5 minutes, stirring, until the sauce coats a spoon.
  5. Season and enrich.
    Add thyme, salt, pepper, and nutmeg if using.
    Stir in Parmesan or vegetarian hard cheese if you like.
    Taste and adjust—this is where Vegetarian Green Bean Casserole with Creamy Mushroom Sauce learns its voice.
  6. Combine.
    Fold beans into the sauce until every piece is glossy and coated.
    If the sauce feels thick, loosen with a splash of warm milk; if thin, simmer 1–2 minutes more.
  7. Top and bake.
    Heat oven to 375°F (190°C).
    Transfer to a 9×13 (or similar) baking dish.
    Crown with a thick, even layer of crispy onions.
    Bake 15–18 minutes until bubbling at the edges and the top is golden.
  8. Rest and serve.
    Let Vegetarian Green Bean Casserole with Creamy Mushroom Sauce sit 5 minutes so layers settle.
    Scoop big, garnish with parsley, and enjoy the creamy-crunchy contrast.

🌈 Benefits Table

Why You’ll Love It What It Delivers Holiday Win
Meat-Free, Satisfying Deep savory flavor, zero meat. Everyone at the table can enjoy.
Creamy + Crunchy Silky center, shattery crown. Classic texture, lighter feel.
Flexible & Friendly Dairy-light or cheese-forward. Easy to adapt for guests.
Make-Ahead Ready Assemble early, bake later. Stress-free timing.
Budget-Smart Everyday ingredients, big payoff. Holiday wow, weeknight simple.

🍄 The Mushroom Move (Flavor Without Meat)

Mushrooms are the “how did this taste so slow-cooked?” secret in Vegetarian Green Bean Casserole with Creamy Mushroom Sauce. Thin slices brown fast, concentrating all that savory goodness. Let them sizzle until the pan looks nearly dry—now add your liquids. You’ll get a sauce that tastes layered, like it simmered for hours, in under ten minutes.

No mushrooms today? Go for it. Add a small splash of soy sauce or Worcestershire-style vegetarian sauce and a pinch of onion powder to mimic that umami backbone.


🧂 Seasoning Roadmap (Layered, Not Loud)

Close-up spoonful of vegetarian green bean casserole with creamy mushroom sauce and crispy onions
Vegetarian Green Bean Casserole 6
  • A pinch of salt with the aromatics
  • Taste again after the sauce thickens (cheese and onions add salt)
  • Freshly ground pepper at the end for cozy warmth
  • Optional lemon zest or tiny squeeze of juice before the bake to lift the creaminess

This soft layering keeps Vegetarian Green Bean Casserole with Creamy Mushroom Sauce bold enough to stand by savory mains without shouting.


🔥 Texture Tips for Satin-Smooth Sauce

  • Warm liquids: Warm broth and milk whisk in silky—no lumps.
  • Cook the starch: If using flour, give it a minute with the fat before adding liquids; if using cornstarch, whisk a smooth slurry first.
  • Gentle simmer: Keep it lively but not boiling hard; the sauce thickens without splitting.
  • Rest before serving: Five minutes post-bake sets layers for pretty scoops of Vegetarian Green Bean Casserole with Creamy Mushroom Sauce.

🌿 Make-It-Yours (Vegetarian Paths)

Cheesy or dairy-light.

  • Cheese-forward: Stir in Parmesan (or rennet-free vegetarian hard cheese) for savory sparkle.
  • Dairy-light: Use almond milk and finish with a small pat of plant butter for sheen.

Fresh, canned, or frozen beans.

  • Fresh = best snap and color.
  • Canned = fastest; drain very well and fold into a slightly thicker sauce.
  • Frozen = thaw, pat dry, and fold in warm.

Crispy topping choices.

  • Classic fried onions (vegetarian brand) for that nostalgic crackle.
  • Buttered panko + onions for extra shatter.
  • Gluten-free version: swap in GF onions/crumbs—your Vegetarian Green Bean Casserole with Creamy Mushroom Sauce stays fabulous.

🥗 What to Serve It With

  • Roasted carrots or maple-chili Brussels sprouts
  • Herby mashed potatoes and vegetarian gravy
  • Wild rice pilaf with cranberries and pecans
  • Honey-balsamic roasted mushrooms for a double-mushroom moment
  • Big green salad with lemon vinaigrette to brighten creamy spoonfuls

This vegetarian dinner recipes staple carries a holiday table and slides into weeknights with ease.


🕒 Make-Ahead, Reheat & Travel

  • Make ahead (up to 2 days): Fold beans into finished sauce; spread in dish; cover and refrigerate. Keep onions separate.
  • Reheat: Bake covered at 350°F (177°C) until hot (20–25 min). Uncover, add onions, and bake 10–12 min more until the crown is golden and crisp.
  • Travel tip: Bring the topping in a bag. Add and finish at your destination so Vegetarian Green Bean Casserole with Creamy Mushroom Sauce lands with peak crunch.

🥣 Troubleshooting (Fast Fixes)

Sauce too thin?
Simmer 2–3 minutes longer, stirring. A small handful of vegetarian Parmesan adds body.

Sauce too thick?
Whisk in warm milk or broth a splash at a time until silky.

Beans too soft?
Blanch 1 minute less next time or fold canned beans very gently and bake a little shorter.

Top not crisp?
Broil 30–60 seconds—watch closely. Keep a small handful of onions to sprinkle at the table for bonus crunch.


🍷 Little Flavor Boosters

  • Fresh thyme leaves scattered after baking
  • A drizzle of good olive oil over the onion crown
  • A pinch of smoked paprika in the sauce for gentle warmth
  • Lemon zest stirred in right before the beans go into the dish

Small touches, big smiles—your Vegetarian Green Bean Casserole with Creamy Mushroom Sauce goes from great to unforgettable.


📌 Quick Recap

Blanch beans.
Soften aromatics; brown mushrooms.
Whisk a silky cream sauce.
Fold in beans.
Crown with crispy onions.
Bake until golden and bubbly.
Rest, scoop, enjoy.

That’s Vegetarian Green Bean Casserole with Creamy Mushroom Sauce—classic comfort, meat-free and magnificent.


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Cheesy Green Bean Casserole Bake
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One-Pot Vegetable Pasta
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“Cravings whisper. Comfort answers. For more cozy green bean casserole recipes, holiday recipes, and thanksgiving side dishes, come find us on Pinterest.”

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45 degree close shot of vegetarian green bean casserole with creamy mushroom sauce and crispy onions

Vegetarian Green Bean Casserole


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  • Author: Ashley Wilson
  • Total Time: 40 minutes
  • Yield: 8 servings 1x
  • Diet: Vegetarian

Description

This Vegetarian Green Bean Casserole with Creamy Mushroom Sauce delivers cozy comfort with no meat needed. Tender green beans, savory mushroom cream, and a golden onion crown—perfect for holidays or weeknights.


Ingredients

Scale

2 lb fresh green beans, trimmed and halved (or 4 cans cut green beans, very well drained)

3 tbsp unsalted butter (or olive oil)

1 small shallot (or ½ onion), finely chopped

3 cloves garlic, minced

1012 oz cremini or button mushrooms, thinly sliced

3 tbsp all-purpose flour (or 2½ tbsp cornstarch mixed with broth for a slurry)

1½ cups low-sodium vegetable broth, warm

1½ cups milk (whole or 2%) or unsweetened almond milk, warm

½ tsp dried thyme (or 1 tsp fresh, chopped)

½ tsp kosher salt, plus more to taste

¼ tsp black or white pepper

Pinch of nutmeg (optional)

½ cup finely grated Parmesan (optional; rennet-free or vegetarian cheese if needed)

2 to cups crispy fried onions (vegetarian brand or homemade)

Chopped parsley to garnish


Instructions

1. Blanch beans: Boil 4–5 min, shock in ice water, drain and pat dry.

2. Sauté shallot in butter/oil until soft; add garlic for 30 sec.

3. Add mushrooms; cook until liquid evaporates and mushrooms brown.

4. Sprinkle in flour and cook 1 min (or use cornstarch slurry).

5. Slowly whisk in warm broth, then warm milk. Simmer 3–5 min until thick.

6. Stir in thyme, salt, pepper, nutmeg, and Parmesan (if using). Taste and adjust.

7. Fold green beans into sauce. Loosen with milk if too thick.

8. Spread in 9×13 dish. Top with crispy onions.

9. Bake at 375°F for 15–18 min until bubbling and golden.

10. Let rest 5 min. Garnish with parsley and serve.

Notes

Make ahead: Assemble casserole without onions and refrigerate up to 2 days.

Reheat: Bake covered at 350°F (20–25 min). Uncover, top with onions, bake 10–12 min more.

Custom swaps: Use almond milk for dairy-light, and rennet-free cheese if fully vegetarian.

  • Prep Time: 20 minutes
  • Cook Time: 20 minutes
  • Category: Side Dish
  • Method: Baking
  • Cuisine: American

Nutrition

  • Serving Size: 1 cup
  • Calories: 240
  • Sugar: 4g
  • Sodium: 400mg
  • Fat: 14g
  • Saturated Fat: 6g
  • Unsaturated Fat: 7g
  • Trans Fat: 0g
  • Carbohydrates: 20g
  • Fiber: 3g
  • Protein: 6g
  • Cholesterol: 20mg

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