Easy Cauliflower au Gratin Recipe

by Joanna
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Learn how to make this Cauliflower au Gratin recipe that will become your all-time favorite side dish recipe. It’s cheesy, slightly crispy on top, incredibly rich, and surprisingly creamy. It’s the best side dish for holiday dinners, and it’s also super easy to make.

Cauliflower au Gratin

This recipe for cauliflower au gratin is a spectacular side dish that’s super easy to prepare. So make this recipe, and learn how to make one of the best cauliflower side dishes with just 10 minutes of prep for an incredible taste.

I love cauliflower since it’s such a versatile ingredient that can be prepared in so many ways and paired with various flavors. One of my all-time favorite cauliflower recipes is this Cauliflower au Gratin, where it’s smothered in a cheesy sauce, making it a delicious treat for your taste buds.

Every time I prepare dinner for my family and friends and need a delicious and easy side dish that doesn’t require much effort, this recipe for cauliflower au gratin is one of my go-to side dishes. 

Just like my cauliflower risotto, air fryer cauliflower, and cauliflower pizza crust recipe, this cauliflower gratin brings another delightful twist to this versatile veggie that everyone loves.

Why Are You Going To Love This Cauliflower Au Gratin

  • Perfect for meal prep. This recipe can be made ahead of time and enjoyed on a busy day for dinner.
  • It’s super easy to make in such a short time.
  • It’s a versatile recipe.
  • It’s an interesting way to include more vegetables into your diet.
  • It pairs perfectly with many main dishes.
  • Made from easy-to-find ingredients.
  • It’s a crowd-pleaser, suitable for family gatherings or dinner parties.

Ingredients Needed

The ingredients for this recipe for cauliflower gratin are simple and easy to find. I’m sure you may already have some in your pantry. Here is a list of everything you will need:

For the Roasted Cauliflower

  • Cauliflower – Use a fresh, medium-sized cauliflower head. Ensure it’s free from blemishes and is firm to touch. Once cleaned, chop it into bite-sized florets for even cooking. 
  • Olive Oil – adds a hint of richness and promotes browning.
  • Salt & pepper – used to balance flavors, enhancing the dish’s taste.

For The Creamy Cheese Sauce

  • Parmesan Cheese – contributes to a rich, cheesy texture in the sauce. Use fresh grated parmesan cheese for the best results.
  • Butter – is used to create a roux in the cheese sauce, providing a creamy and silky base.
  • Garlic Cloves – use fresh minced garlic to infuse the creamy cheese sauce with its distinctive, aromatic flavor.
  • Heavy Cream – Provides a luscious, creamy texture to the cheese sauce.
  • Low-Sodium Broth – Adds depth of flavor to the cheese sauce. You can also use milk instead of low-sodium broth.
  • Cheddar Cheese – feel free to use your favorite type of cheese. I used cheddar cheese since it melts beautifully, creating a creamy texture.
  • Nutmeg – enhances the sauce’s flavor with a hint of warmth and complexity. You can skip it if you are not a fan of this type of spice.
  • Salt & pepper – it helps balance all the flavors in this creamy sauce.
  • Parsley – you will need fresh chopped parsley to garnish.

How To Make Cauliflower Au Gratin

If you follow these easy next steps, you will end up with a perfectly cheesy cauliflower au gratin that is deliciously eaten simply as it is, or it can be paired with so many other dishes.

Prepare The Cauliflower

Start by preheating your oven to 400°F (200°C). This step ensures that your oven is ready to roast the cauliflower to perfection. You can also skip the baking process and boil the cauliflower on the stove for 5 minutes until slightly tender.

Wash the cauliflower head under cold running water and use a kitchen towel to pat it dry thoroughly. This step is essential to prevent excess moisture, allowing the cauliflower to roast evenly and develop a golden color.

Cut the cauliflower head into bite-sized florets using a sharp knife, then place them on a large baking sheet.

Drizzle them with olive oil and toss the florets gently with your hands to ensure an even distribution of the oil. Season with sea salt and freshly ground black pepper. 

Roast the cauliflower for 15-20 minutes or until the florets become tender and develop a light golden color. Keep a close eye on the roasting process to avoid overcooking, which can lead to mushy cauliflower.

Prepare The Cheese Sauce

While the cauliflower is roasting in the oven, it’s time to create the luscious cheese sauce that will elevate your dish.

Cook the Garlic. Add the butter in a large saucepan over medium heat. Once melted, add the garlic and sauté for approximately 1 minute or until it becomes fragrant. Be careful to prevent it from browning, as this can lead to a bitter taste.

Stir In the Broth. Pour in the broth, adding a pinch of salt, freshly ground pepper, and a touch of nutmeg (for a warm, aromatic note). 

Pour in the Heavy Cream: Gently pour the heavy cream into the saucepan, whisking continuously. 

Simmer and Adjust Heat: Allow the mixture to simmer gently. You can lower the heat slightly to maintain a steady simmer. 

Incorporate Cheeses: Gradually incorporate the Parmesan cheese and 1 cup of cheddar cheese into the sauce. Continue to whisk to allow the cheeses to melt seamlessly into the sauce, creating a smooth and velvety texture.

Adjust Thickness: If you desire a thicker sauce, add a pinch of xanthan gum or a sprinkle of gluten-free flour. Whisk it in until the sauce reaches the desired thickness. 

Assemble the Cauliflower Casserole

Carefully transfer the perfectly roasted cauliflower florets from the baking sheet to the bottom of a baking dish, ensuring the cauliflower is evenly spread in a single layer.

Now, pour the prepared creamy cheese sauce over the roasted cauliflower. Gently toss the cauliflower and sauce together until they are well combined, then sprinkle the remaining shredded cheddar cheese evenly over the top of the cauliflower and sauce.

Bake the Cauliflower Gratin

Preheat your oven to 400°F (200°C), and then place the assembled gratin in the preheated oven. Bake for 25-30 minutes or until the gratin is bubbling and the cheese on top has achieved a delicious golden-brown color. 

For a final touch of color, freshness, and added flavor, consider garnishing your Cauliflower au Gratin with fresh parsley or chives. 

Cauliflower au Gratin

Tips For Making Cauliflower Au Gratin

  • Use Fresh Cauliflower: When making cauliflower au gratin, choose a fresh, firm cauliflower head with vibrant white florets and green leaves. Avoid cauliflower that appears wilted or has brown spots.
  • Even Floret Sizes: When cutting the cauliflower into florets, aim for even sizes. This ensures uniform cooking, preventing some pieces from being overcooked while others remain undercooked.
  • Properly Dry the Cauliflower: After washing the cauliflower, pat it dry with a kitchen towel. Excess moisture can affect the roasting process and lead to uneven browning.
  • Keep an Eye on Roasting Time: Monitor the cauliflower closely in the oven. Roasting times can vary depending on the size of the florets and your oven, so it’s important to check for tenderness.
  • Whisk Continuously: While making the cheese sauce, whisk continuously to prevent lumps and ensure a smooth, velvety texture.
  • Thicken the Sauce: If you desire a thicker sauce, consider adding a pinch of xanthan gum or a sprinkle of gluten-free flour. Whisk it in until the sauce reaches the desired thickness.
  • Evenly Coat Cauliflower with Sauce: When combining the cauliflower and sauce, toss them together thoroughly to ensure that every floret is coated evenly.
  • Watch the Baking Time: Keep a close eye on the gratin while baking to prevent over-browning. It should be bubbly with a golden-brown cheese crust when it’s done.

Recipe Variations

  • Broccoli and Cauliflower Gratin: Combine cauliflower with broccoli for a colorful and nutritious gratin. Combining these cruciferous vegetables creates a delightful contrast in flavor and texture.
  • Cauliflower and Bacon Gratin: Add cooked bacon pieces to the gratin for a savory, smoky flavor. 
  • Spicy Cauliflower Gratin: Infuse heat into your gratin by adding red pepper flakes or a touch of hot sauce to the cheese sauce. It’s a delightful twist for those who enjoy a spicy kick.
  • Vegan Cauliflower Gratin: Replace dairy with plant-based alternatives. Use vegan butter, non-dairy milk, and cheese to create a dairy-free and vegan-friendly cauliflower gratin.
  • Herb-Infused Gratin: Incorporate fresh herbs like thyme, rosemary, or chives into the cheese sauce for a fragrant and aromatic variation.
  • Indian-Spiced Cauliflower Gratin: Season the cauliflower with Indian spices like cumin, coriander, and turmeric, and use coconut milk in the cheese sauce for a fusion of flavors.
  • Mashed Cauliflower Gratin: Instead of cauliflower florets, use mashed cauliflower as a base. This variation is similar to mashed potatoes but with the creaminess of cauliflower.
Cauliflower au Gratin

Storing Ideas

  • Fridge: If you have any cauliflower au gratin leftovers, allow them to cool to room temperature, then transfer them to an airtight container and store them in the fridge for up to 3-4 days. 
  • Freezer: While it’s possible to freeze Cauliflower au Gratin, remember that the texture may change slightly upon thawing. To freeze, place the cooled gratin in a freezer-safe container and store it for 1-2 months in the freezer. Thaw in the refrigerator before reheating.

Can I Use Frozen Cauliflower?

While fresh cauliflower is recommended for the best texture, you can use frozen cauliflower in a pinch. However, be sure to thaw and drain it well before use, and the texture may differ slightly.

 Can I Make This Cauliflower Gratin In Advance?

 Yes, you can make Cauliflower Gratin in advance. Prepare the ingredients separately and assemble and bake them right before your event to ensure the best texture and flavor.

More Cauliflower Recipes

Cauliflower au Gratin

Cauliflower au Gratin

5 from 1 vote

Prep time 10 minutes
Cook Time 20 minutes
Yelds 8 servings


Learn how to make this Cauliflower au Gratin recipe that will become your all-time favorite side dish recipe. It's cheesy, slightly crispy on top, incredibly rich, and surprisingly creamy. It’s the best side dish for holiday dinners, and it's also super easy to make.


  • 1 large head of cauliflower cut into 8 cups of bite-sized florets
  • 2 tbsp extra-virgin olive oil
  • Sea salt and freshly ground black pepper to taste

For the Creamy Cheese Sauce:

  • ½ cup Parmesan cheese freshly grated
  • 3 tbsp unsalted butter
  • 3 garlic cloves minced
  • 1 cup heavy cream
  • 1/2 cup low-sodium broth or milk
  • 1 1/2 cups sharp cheddar cheese shredded and divided
  • A pinch of ground nutmeg
  • ½ tsp sea salt or to taste
  • ½ tsp freshly ground black pepper or to taste

For Garnish (optional):

  • Fresh parsley or chives chopped


Prepare the Cauliflower:

  • Preheat your oven to 400°F (200°C).
  • Gently wash the cauliflower head and pat dry. Break into bite-sized florets.
  • On a large baking sheet, toss the cauliflower with olive oil and sprinkle with sea salt and freshly ground black pepper to coat evenly.
  • Roast in the preheated oven for 15-20 minutes or until the florets are tender and have a light golden color.

Make the Cheese Sauce:

  • While the cauliflower is roasting, begin making the sauce sauce. Over medium heat, melt the butter in a large saucepan.
  • Add the minced garlic and sauté for about 1 minute until fragrant, ensuring not to let it brown.
  • Stir in the broth, adding a pinch of salt, pepper, and nutmeg. Gently pour in the heavy cream, whisking continuously.
  • Allow the mixture to simmer, then lower the heat slightly.
  • Gradually mix in the Parmesan and 1 cup of the cheddar until the cheese has melted into the sauce and it’s smooth and velvety. For a thicker consistency, consider whisking in a pinch of xanthan gum or a sprinkle of gluten-free flour until the desired thickness is achieved.

Assemble the Cauliflower Casserole:

  • Transfer the roasted cauliflower to the bottom of an 8×11 or 9×13-inch baking dish.
  • Pour the creamy cheese sauce over the cauliflower and toss until well combined.
  • Sprinkle the remaining ½ cup of shredded cheddar cheese.

Bake the Gratin:

  • Bake in the oven for 25-30 minutes or until the gratin is bubbly and the cheese is golden brown on top.

Final Touches:

  • Optionally, garnish with fresh parsley or chives for a burst of color and freshness.
  • Let it stand for a few minutes before serving to allow the sauce to set slightly.

Serve and Enjoy:

  • This indulgent Cauliflower Gratin is now ready to be served as a delightful side dish or a vegetarian main course that's sure to impress.


Chef’s Notes:
  • For a gluten-free version, ensure that the broth and any thickening agents used are certified gluten-free.
  • Feel free to adjust the seasoning according to your preference, and add a dash of paprika or cayenne pepper for an extra kick.
  • The gratin can be prepared ahead of time and refrigerated, then baked just before serving for a convenient entertaining option.
Nutrition Facts
Amount per serving.
Total Carbs
Net Carbs

How do we calculate the nutrition info?

These nutrition facts listed are determined using nutrition information from the USDA Food Database. Our nutrition facts are accurate, but if you are using different products, please make your calculations. Net carb count is calculated by subtracting both fiber and sugar alcohols because they don’t raise blood sugar.

Course Side Dish
Cuisine American
Keyword Cauliflower au Gratin
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5 from 1 vote (1 rating without comment)

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