Creamy Vegan Cauliflower Casserole with Cheesy Cashew Sauce

This Vegan Cheesy Cauliflower Casserole is filled with tender cauliflower and mushrooms baked in a creamy dairy-free cheese sauce. It’s an easy, healthy and satisfying side or main for weeknights and holidays alike.

Cauliflower can seem bland or become mushy if overcooked, but when treated well it’s incredibly versatile. From cauliflower gnocchi to roasted steaks or crispy wings, it can transform into exciting dishes. You don’t need to get fancy to make cauliflower shine — this creamy Vegan Cheesy Cauliflower Casserole is a simple way to elevate it.

Picture tender cauliflower florets combined with sautéed mushrooms and onions, all baked in a rich, dairy-free cheese sauce and finished with a crunchy breadcrumb or vegan cheese topping. It’s comforting, flavorful, and satisfying — a great alternative to traditional gratins.

Ingredients to Make Cheesy Vegan Cauliflower Mushroom Casserole

The base of this casserole is cauliflower, with mushrooms and onions added for texture and flavor. The standout is the dairy-free cheese sauce made from cashews and cashew milk, brightened with lemon and garlic, boosted with miso and nutritional yeast, and thickened with tapioca starch for a stretchy, melty texture.

Tapioca starch is key here: it works as a gluten-free thickener and gives the sauce that desirable stretchy quality you want in a melty “cheese” sauce. For a finish, choose either vegan shredded cheese or a savory breadcrumb topping.

How to Make Vegan Cheesy Cauliflower Casserole

1. Steam cauliflower until just fork-tender.
2. Sauté onions and mushrooms until lightly browned.
3. Blend the cheese sauce ingredients until smooth.
4. Heat the blended sauce in a saucepan, stirring until it thickens and becomes glossy.
5. Combine the cauliflower, mushrooms and onions in your baking dish, pour in the sauce and stir to coat evenly.
6. Top with vegan shredded cheese or the breadcrumb mixture, then bake until bubbly and lightly golden.

How to Make Vegan Cauliflower Casserole Ahead of Time

Prepare the casserole as directed up to the point of adding the topping. Once the sauce has cooled, cover and refrigerate the assembled dish for up to one day. When ready to bake, add the breadcrumb or vegan cheese topping and bake according to the instructions.

How to Properly Store Cauliflower Casserole

Leftovers keep well in an airtight container in the refrigerator for up to 3 days. Reheat in a 400°F (200°C) oven for 5–8 minutes or microwave for about 2 minutes on high until warmed through.

Helpful Equipment to Make This Recipe

• Baking dishes: Two 8×8 inch baking dishes or one 9×13 inch baking dish
• High-speed blender: useful for a silky-smooth sauce

Names like vegan cauliflower gratin, cheesy cauliflower bake, or cauliflower casserole all describe the same comforting dish. Whichever you call it, this casserole is easy to make and a great addition to holiday tables or casual weeknight meals.

I hope you try this Vegan Cheesy Cauliflower Casserole and enjoy it as much as I do. It’s a crowd-pleasing, plant-based comfort dish that works as a side or a satisfying main.

Craving More Vegan “Cheese” Recipes? Try These Next!

• Cauliflower Gnocchi Mac n’ Cheese
• Broccoli Mac n’ Cheese Soup
• Vegan Supreme Mac n’ Cheese
• The Best Vegan Cheese Sauce

If you make this Vegan Cheesy Cauliflower Casserole, please leave a comment and rating or tag @okonomikitchen on Instagram — I love seeing your recreations! Hungry for more? Subscribe to the newsletter and follow on social media for more plant-based recipes.

Vegan Cheesy Cauliflower Casserole

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5 Stars

5 from 3 reviews

• Author: Lisa Kitahara
• Total Time: 60 minutes
• Yield: 8 Servings

SAVE IT FOR LATER! ↓

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