Cauliflower Au Gratin

5 from 2 votes

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Creamy and flavorful Cauliflower Au Gratin uses only a few simple ingredients and is an easy side dish perfect for Thanksgiving or any other weekday! Similar to Scalloped Potatoes but made with cauliflower, this low-carb, cheesy side dish is what dreams are made of.

baked cauliflower au gratin

Cauliflower Au Gratin…The Perfect Side Dish

Whether I need a fast veggie-packed side dish during the week or want something creamy and cheesy for the holidays, I love making this Cauliflower Gratin. While the sauce is creamy and silky smooth, the cauliflower keeps it light and easy on the carbs so you can feel a little better about this recipe versus Funeral Potatoes or Mashed Potatoes.

While I big puffy heart eyes LOVE potatoes, cauliflower is the healthier cousin that tastes nearly as good. Topping steamed cauliflower with a creamy sauce, finishing it off with grated cheddar cheese and baking it into a creamy and cheesy casserole becomes a great addition to nearly any meal.

whisking white sauce in pan

Ingredients Needed for Cauliflower Au Gratin

You only need a few ingredients that taste beyond amazing together. Here is everything you need to make this amazingly creamy Cauliflower Au Gratin:

  • Cauliflower – the main ingredient! Cauliflower is the perfect veggie to deliver creamy, cheesy goodness straight to you.
  • Butter + Onions – butter is used to saute the onions and make a roux. While the subtle flavor of onions makes a great base for any casserole dish.
  • Flour – this creates a roux, which is a much more stable sauce for leftovers.
  • Milk + Heavy Cream – both are used here to thin out the sauce but still keep it nice and creamy.
  • Cheddar Cheese – delicious sharp cheddar cheese tops this whole dish. For the best melting results, buy a block and shred the cheese yourself.
  • Nutmeg, Salt + Pepper – Nutmeg is a classic ingredient for a roux and salt and pepper keep this seasoned well.
cauliflower in baking dish

How to Make Cauliflower Au Gratin

Really simple recipe steps here. It may seem like a lot of steps but rest assured this is much easier to make than you think. For full details and increments, scroll down to the printable recipe card at the bottom of this post.

  1. Preheat oven. Chop up your onions and cauliflower into bite-sized pieces.
  2. Next, steam some cauliflower florets until fork tender.
  3. Brown some onions in butter–be sure to get them really brown! That is where a lot of this flavor comes from.
  4. Whisk in the flour to make a roux, and cook for 1-2 minutes.
  5. Whisk in the milk. Season with salt, pepper and nutmeg.
  6. Remove from heat and stir in the heavy cream. Then finally, pour it over steamed cauliflower in the baking dish.
  7. Sprinkle with cheese and bake!
  8. Tada! Cauliflower au Gratin.
cauliflower and gratin sauce in baking dish


Before making this recipe, consider these variations to take your Cauliflower Au Gratin to the next level!

  • Bacon – I am a firm believer that bacon makes everything taste better. Simply cook bacon, chop into pieces and drain most of the fat. Omit the butter and sauté the onions. Then proceed as normal!
  • Toppings – you can add chips or just about any other crunchy topping. French fried onions, ritz crackers, breadcrumbs, corn flakes, Sour Cream and Onion Chips, etc.. Feel free to switch it up based on what you have on hand.
  • Using Different Cheeses– while cheddar cheese is a great, all-purpose cheese, try using parmesan, gruyere, blue cheese or even goat cheese for a new and interesting flavored Cauliflower au Gratin.
grated cheddar cheese on cauliflower au gratin

More Cauliflower Recipes to Try!

Looking for even more cauliflower recipes? Here are some!

Piping hot, creamy, toasty, and a little oniony too. Cauliflower Au Gratin is a really simple and delicious side for the holidays. Be sure to print/save/bookmark/pin/share this recipe because it’s a tasty one!

Have a great day, friends!

cauliflower au gratin on white plate
baked cauliflower au gratin
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5 from 2 votes

Cauliflower Au Gratin

Creamy, flavorful Cauliflower Au Gratin uses only a few simple ingredients and is an easy side dish perfect for Thanksgiving or any other day!
servings 6 servings
Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes


  • 1 head cauliflower cut into bite size pieces
  • 1 small onion diced
  • 3 tablespoons butter
  • 4 tablespoons all purpose flour
  • 1 1/2 cups whole milk
  • 1/2 cup heavy cream
  • salt & pepper to taste
  • 1/4 teaspoon ground nutmeg
  • 1 cup cheddar cheese grated


  • Preheat oven to 400 degrees. Chop cauliflower into bite size pieces.
    cauliflower florets on cutting board
  • Steam cauliflower until fork tender. Drain really well. Place into buttered baking dish and set aside.
    steamed cauliflower in baking dish
  • While cauliflower is cooking, heat butter over medium heat in deep cast iron skillet. Saute onions until tender and brown, 5-7 minutes.
    onions cooking in butter in skillet
  • Whisk in flour to make a roux and cook for 2 minutes.
    flour, onion and butter cooking in pan
  • Add in milk, salt, pepper and nutmeg. Whisk until simmering and sauce has thickened.
    whisking white sauce in pan
  • Remove from heat and add in heavy cream.
    pouring heavy cream into white sauce
  • Pour sauce over steamed cauliflower.
    pouring white sauce over cauliflower
  • Top with cheese and bake 15 minutes. Serve hot.
    grated cheddar cheese on cauliflower au gratin


Calories: 279kcal | Carbohydrates: 13g | Protein: 10g | Fat: 22g | Saturated Fat: 13g | Cholesterol: 68mg | Sodium: 230mg | Potassium: 417mg | Fiber: 2g | Sugar: 6g | Vitamin A: 754IU | Vitamin C: 47mg | Calcium: 243mg | Iron: 1mg
Course: Side Dish
Cuisine: American
Keyword: cauliflower au gratin
5 from 2 votes

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Recipe Rating

4 Responses
  1. JGee

    5 stars
    I made this for Thanksgiving and everyone loved it! The people who don’t like veggies even loved it! Putting into the rotation for regular family dinners!!

  2. Diana

    How are there NO comments on this yet. #peopledontknowwhattheyaremissing. Haha, I’m not a hashtagger–but kudos to your good use of them.

    I have just been perusing the internet for cauliflower recipes, and walah, bam, YOU deliver.

    But, I don’t have Kettle in my home. Better go get some.