Cauliflower au gratin

This recipe for cauliflower au gratin is creamy, cheesy, and delicious. In addition to being tasty, it is suitable for people with a wide variety of dietary restrictions. All of the ingredients in this recipe are gluten free, vegetarian, egg free, nut free, and keto friendly. 

This recipe also includes tips on how to prevent cheese sauce from curdling. Keep these tips in mind next time you make cauliflower au gratin, au gratin potatoes, mac and cheese, or any other dish with a cheese based sauce. If you need even more tips you can check out our article on how to prevent your cheese sauce from getting gritty, grainy, and curdled

Cauliflower au gratin - keto, gluten free, vegetarian

Ingredients that prevent cheese sauce from curdling

Do you ever wonder how busy restaurants with bustling kitchens cook large batches of cheese sauce without allowing them to curdle? Many restaurants and industrial kitchens use ingredients that stabilize cheese sauces and prevent them from curdling. Incorporating one of these ingredients into your dish is the easiest way to ensure your sauce comes out silky smooth. 

Sodium citrate is one example of an ingredient that stabilizes cheese sauce. Sodium citrate is found in processed cheeses such as American cheese and Velveeta cheese, so adding a slice of American cheese to a sauce will make it much easier to work with. Other common household staples such as cream cheese contain gums that also stabilize cheese sauces. I use cream cheese in my cauliflower au gratin recipe.  

Other tips for preventing cheese sauce from curdling

Here are some additional tips to prevent your cheese sauce from curdling when you make cauliflower au gratin. 

  • Add starch to the cheese sauce. In my cauliflower au gratin recipe I use gluten free all purpose flour.
  • Use cream rather than milk as the sauce base. The high fat content in cream protects against curdling. 
  • Keep the heat as low as possible after the cheese is added to the sauce. The sauce base should already be warm enough to melt the cheese. I turn the heat off entirely before adding the cheese when I make cauliflower au gratin. 
  • Continuously stir the sauce after the cheese is added. Stir until the cheese is fully melted. This will prevent any one area of the pot from getting too warm. 
  • Grate the cheese as finely as possible before adding it to the sauce. The cheese will melt faster and more evenly at lower heats. 
  • Allow the cheese to warm up to room temperature before adding it to the cheese sauce. Cheese sauce is more likely to curdle if cold cheese is added to a hot base due to abrupt temperature increase.
  • Use block cheese rather than pre-shredded cheese to make cheese sauce. Shredded cheeses are coated in anti-caking ingredients which affect the way the cheese melts. I always use block cheese when making cauliflower au gratin.

Cauliflower au gratin - keto, gluten free, vegetarian

The secret to making a delicious cheese sauce for cauliflower au gratin (or anything else)

There are 3 ingredients I recommend adding to any cheese sauce to step the flavor up to the next level. These ingredients are nutmeg, mustard, and hot sauce. They are all included in my recipe for cauliflower au gratin. Nutmeg is a staple for cream based sauces and is commonly used in dishes such fettuccini alfredo and au gratin potatoes. Mustard pairs well with most cheeses and has the added benefit of being an emulsifier (like sodium citrate). This means that adding mustard will help your sauce maintain a silky smooth texture. The hot sauce is probably the least crucial of the three ingredients, but it brings a nice touch of acidity to the dish.

Choosing a cheese for cauliflower au gratin

I like to use a nutty cheese like smoked gouda or gruyere for my cauliflower au gratin. If these are hard to find near you, or if they are too expensive, you can always use a more common cheese. I recommend using a cheese with a strong flavor. One option would be to use 1 1/3 cups of sharp cheddar rather than 1/3. 

Cauliflower au gratin

This cheesy cauliflower au gratin is gluten free, vegetarian, egg free, nut free, and keto friendly.
Prep Time5 minutes
Cook Time25 minutes
Total Time30 minutes
Course: Side Dish
Keyword: egg free, gluten free, keto, nut free, vegetarian
Servings: 4 people


  • 1 head cauliflower
  • 2/3 cup heavy cream
  • 1/3 cup sour cream (sub greek yogurt)
  • 1 cup shredded smoked gouda (sub gruyere or sharp cheddar)
  • 1/3 cup sharp cheddar
  • 1 tbsp cream cheese
  • 1/2 tbsp butter
  • 1/2 tbsp all purpose gluten free flour (sub almond flower if keto)
  • 1/4 tsp nutmeg
  • 1/4 tsp mustard powder
  • 1/4 tsp hot sauce
  • 1/2 tsp olive oil
  • 1 tsp chives
  • 1 tsp green onions


  • Preheat your oven to 450 degrees. Chop the chives and green onions and shred any cheese that is not already shredded
  • Chop the cauliflower into bite-sized pieces and toss it in olive oil and salt. Bake the cauliflower for 25 minutes. While your cauliflower is baking, you can move on to the next step.
  • Add the butter and flour to a pan and cook over medium heat for 3-5 minutes.
  • Add the cream, sour cream, cream cheese, nutmeg, mustard, and hot sauce to the pot and stir until the cream cheese and sour cream melt
  • Turn off the stove and add the shredded cheese, chives, and green onions to the pot. Stir continuously until the cheese melts. When the cauliflower is done roasting, add it to the pot and mix well
  • Optional: Put your completed dish in an oven safe container and broil for 1-2 minutes to brown

Enhancements for cauliflower au gratin

There is no reason you have to limit yourself to just cauliflower when you make this dish. It is easy to add extra vegetables to cauliflower au gratin.

I would recommend adding tomatoes, broccoli, or Brussels sprouts. If you add broccoli or Brussels sprouts to the cauliflower, you should roast these vegetables in the oven when you roast the cauliflower. I recommend tossing quartered Brussels sprouts or bite-sized pieces of broccoli in olive oil and adding them to the oven 5-10 minutes after the cauliflower. They will cook for 15-20 minutes. If you add tomatoes to the cauliflower au gratin I would chop the tomatoes in small pieces and add them right after you add the cheese to the cheese sauce.

Adding extra toppings to your cauliflower au gratin is another easy way to elevate the dish. I recommend adding crispy onions or gluten free breadcrumbs on top of the dish. If you choose to add breadcrumbs to your cauliflower au gratin you should toast 1/3 cup of bread crumbs in 1/2 tsp of olive oil for about 5 minutes and add them to the top of the cauliflower au gratin when it is done.

Other recipes you might be interested in

roasted asparagus

If you like our cauliflower au gratin you might also like our roasted asparagus with greed goddess. This is another keto vegetable side that is paired with a creamy element.

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