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This cheesy, yet dairy free Vegan Cauliflower Gratin is the perfect side dish for holidays or family dinners. Loaded with veggies and ready in 30 minutes!

The great news about this Vegan Cauliflower Gratin is that it’s proof you don’t need loads of dairy to make a creamy and indulgent au gratin side dish. You’ll find layers of tender cauliflower, spinach, mushrooms, and a cheesy, dairy free cream sauce in every bite. Enjoy it as a holiday side dish along with this vegan green bean casserole or save it for weeknight dinners.
All of the layers take minutes to prepare on the stove: cooked cauliflower, a vegan cream sauce, and sauteed vegetables. Stir them all together, bake, then enjoy! It’s a quick 30-minute side that everyone will want more of.
Recipe features
- The veggie layers and creamy sauce come together easily on the stove before they’re all baked together in a casserole dish.
- Enjoy it as a healthy holiday side dish or for a quick 30-minute side dish on weeknights.
- Just as indulgent as my Cheesy Cauliflower Bake, but will leave you feeling light thanks to all of the veggies!
- Naturally vegan, nut free, and easy to make gluten free.
What is cauliflower au gratin?
Traditional cauliflower au gratin recipes are made with steamed cauliflower florets that are smothered in a béchamel or cream sauce with Gruyere cheese. The cheesy side dish is finished with a buttered breadcrumb topping, then baked until bubbly.
My vegan version is slightly different. Instead of a true béchamel, a sauce made with a dairy free milk base and thickened with cornstarch surrounds the vegetables while replicating that creamy texture. It’s nice and cheesy, just like the classic, thanks to a mix of nutritional yeast, vegan parmesan, and tender cauliflower.
Ingredients
This is a snapshot of the key ingredients needed for a vegan cauliflower bake. For the full list, scroll down to the recipe card below.
- Cauliflower - Either chop a head of cauliflower into florets yourself or buy pre-chopped cauliflower to save some time.
- Mushrooms and spinach - These are sautéed and added to the cauliflower casserole.
- Dairy-free milk - Any dairy free milk will work here. If you don’t need the dish to be vegan, go ahead and use regular milk instead.
- Cornstarch - This will help thicken the creamy sauce so your casserole doesn’t turn out watery.
- Breadcrumbs - Panko breadcrumbs will add a nice crunch on top of the casserole. For a gluten free cauliflower gratin, use your favorite gluten free breadcrumbs instead.
- Vegan parmesan - You can use store-bought vegan parmesan cheese or make it yourself using this recipe from Minimalist Baker.
Step-by-step instructions
Step 1: Cook the cauliflower. To begin, cook the cauliflower in boiling water until it’s fork tender. Drain, then set aside.
Step 2: Cook the vegetables. Melt the butter in a skillet over medium heat while you wait for the cauliflower. Add the onion and mushrooms, and sauté until soft. Next, add the garlic and spinach to the pan.
Step 3: Make the creamy sauce. Whisk the milk, vegetable broth, nutritional yeast, and cornstarch together in a bowl, then pour it into the skillet. Let the sauce simmer until it thickens slightly, then take it off the heat and stir in the cauliflower.
Step 4: Bake the casserole. Transfer the cauliflower mixture to a casserole dish and add the breadcrumbs and vegan parmesan on top. Bake until the sauce is bubbly, then broil for a few minutes to help the breadcrumbs brown. Serve with fresh parsley on top and enjoy!
Tips and FAQs
- Steam the cauliflower florets if you don’t want to boil them.
- To make this an almost one pan recipe, prepare the vegetable and creamy cauliflower filling and bake the casserole in an oven-safe or cast-iron pan instead.
- Stir crumbled tempeh bacon in with the cauliflower and cream sauce for delicious smoky bites.
- Or stir shredded vegan cheese into the casserole for stretchy, cheesy pulls with each scoop.
- This gratin recipe is lightly seasoned to keep the flavor mild. If you’re craving a little more warmth and herbaceousness, mix dried oregano, basil, sage, thyme, or paprika in with the sauteed vegetables or breadcrumb topping.
Can I use frozen cauliflower?
Yes, you can use frozen cauliflower instead of fresh here. Make sure the frozen florets are thawed and drained of excess moisture before stirring them into the skillet with the sauce and vegetables.
What do you serve with vegan cauliflower gratin?
Usually, this dairy-full side dish is fantastic on the side of a whole roasted chicken, the Thanksgiving turkey, meatloaf, or glazed ham. But because this is a vegan recipe after all, I recommend keeping the mains a little lighter and veggie-forward. Try it on the side of roasted artichokes, stuffed peppers, or lentil lasagna.
Storage
- Refrigerator: Let the leftover vegan gratin cool completely before transferring it to an airtight container. Store in the fridge for up to 5 days.
- Reheating: Reheat individual portions for 1 to 2 minutes in the microwave or pop the whole casserole into a 350ºF oven to help the breadcrumbs crisp again.
More easy cauliflower recipes
If you made this recipe, be sure to leave a comment and star rating below. Thanks!
Vegan Cauliflower Gratin
Ingredients
- 1 head cauliflower cut into florets
- ¼ cup vegan butter
- 1 cup yellow onion diced
- 8 oz. bella mushrooms sliced
- 5 garlic cloves minced
- 5 oz. spinach chopped
- ½ cup almond milk or milk of choice
- ¼ cup vegetable broth
- 2 tablespoon nutritional yeast
- 2 tablespoon cornstarch or more
- ¼ cup breadcrumbs
- ¼ cup vegan parmesan cheese
- salt and pepper to taste
- fresh parsley for garnish
Instructions
- Preheat oven to 375°. Place the cauliflower into a large saucepan and fill it with water until it covers the cauliflower. Bring it to a boil, then cook for about 3 minutes until it can easily be pierced with a fork; drain then set aside.
- Meanwhile, melt the butter in a large skillet over medium heat, then add the onion and mushrooms and sauté until soft, about 8 minutes.
- Add the garlic and spinach to the skillet and sauté for 2 minutes until the spinach is wilted. Whisk the milk, vegetable broth, nutritional yeast, and cornstarch together in a bowl, then pour it into the skillet. Simmer over medium-low heat until the sauce has thickened, 2-3 minutes. Remove the skillet from the heat, then add the cauliflower and stir to coat. Add salt and pepper to taste.
- Grease an 8x8 or 9x9 baking dish with nonstick spray, then pour the cauliflower mixture into the dish. Sprinkle breadcrumbs and vegan parmesan overtop.
- Place the dish in the oven and bake for 14 minutes, then broil for 1-2 minutes until the breadcrumbs are golden on top. Sprinkle with fresh parsley (optional) and enjoy!
Notes
Nutrition
UPDATE NOTE: This post was originally published in January 2018. It was updated with new text and photos in November 2022.
Snewpea says
This was good! I actually made it vegetarian because I was trying it out for Christmas Eve. It took a lot longer than 15 min to prep ..so I'm wondering if it can be made ahead (minus the breadcrumbs and cheese on top until it goes in the oven)? If so, what would we then cook it at if it's cold.or room temp?
Erin says
I'm glad you liked it! Yes, it can definitely be prepped ahead of time and stored in a covered dish in the refrigerator. As you said, wait to add the breadcrumbs and cheese until you're ready to bake it. Keep the oven temp the same, but you may need to bake it for an extra 5 minutes if you're putting it straight from the refrigerator into the oven.
Kelly @ Kelly Runs For Food says
Oooh yeah I want this! I love cashew "cheese" so much!