You’re probably familiar with using sweetpotatoes in a standard gratin recipe – but what about swapping things around and using the sweetpotatoes in the sauce? This cauliflower gratin is a veggie-packed side dish with a cheesy sweetpotato sauce that is rich, creamy, and offers a nutritional boost compared to other recipes. As a dietitian, I love how this lightened-up recipe features 12 grams of protein per serving. Perfect for the holidays – but also great for regular family dinners this season.
Disclosure: This recipe was developed in a paid partnership with the North Carolina Sweetpotato Commission.
Ingredients
Here’s a photo of all the ingredients you’ll need, along with selected ingredient notes:
- Sweetpotatoes: The star of the sauce! Not only does it add flavor and depth to the cheese sauce, but it also helps thicken it (so no cream is needed) and adds extra phytonutrients.
- Cauliflower: You’ll want two heads of cauliflower that weigh about 3 pounds combined before chopping into florets. A bit more or a bit less are fine; just keep in mind it may affect the total yield of the recipe.
- Cheese: A blend of sharp cheddar and Parmesan is my favorite combo, but you can use the more classic Gruyère if you prefer.
Instructions
You’ll find the full recipe amounts and instructions in the recipe card below, but here’s a helpful overview with photos and tips.
Start by boiling the cauliflower florets for about five minutes. The goal is to have them just starting to turn tender, but not mushy, as they will continue to cook in the oven once in the casserole dish.
Use a slotted spoon to remove the cauliflower and set aside in a bowl. This way, you can leave the hot water in the pot and cook the sweetpotatoes in it (saves times since you don’t have to wait for more water to boil!).
Add the sweetpotatoes to the pot and boil for 10 minutes, until they’re tender. Drain them then pour them into the bowl of a mini food processor. Let them cool for a few minutes, then puree. Quick tip: make sure to leave the spout open on the processor so that heat doesn’t pressurize the contents! Otherwise, the hot food can splatter when you open it.
If you don’t have a mini food processor, just mash the sweetpotatoes by hand using a potato masher or fork. Try to get them as smooth as possible.
In the same empty pot you’ve been using (yay for minimal dishes), heat the butter over medium heat. Add the garlic and cook for a minute until it’s nice and fragrant. Then add the flour and cook for another minute, until it turns a light golden color (see photo below).
Add the milk little by little, stirring each time, so that everything is nicely incorporated.
Add the salt, paprika, pepper, nutmeg, and pureed sweetpotatoes to the milk mixture. Cook for a few minutes, stirring often, until everything is combined.
Add ½ cup of the cheddar and ¼ cup of the parmesan (you’re going to save the rest for topping). Cook until the cheese has melted into the sauce.
Almost done! Spread a layer of the sweetpotato cheese sauce in the casserole dish. Dab the bowl of cauliflower with paper towels to make sure as much moisture is removed as possible, then pour the cauliflower into the casserole dish. Top with the cheese sauce, then add the remaining cheddar, parmesan, and breadcrumbs. Drizzle a little olive oil on top and now it’s ready to bake!
Pop that in the oven for about 25-35 minutes, until the mixture is bubbly and the top is lightly browned.
Let that cool for at least 15 minutes – if you try to serve it too soon, the sauce can be a little runny. It will thicken quite a bit with just a little cooling time. Serve warm and enjoy!
Recipe FAQ
Here are some common questions that may come up as you’re preparing this recipe:
Yes. Instead of boiling per the recipe, follow the package directions but cook for about half the recommended time so that the cauliflower is still a bit firm. Drain well and dry with paper towels to remove as much moisture as possible. Then layer in the casserole dish with the sweetpotato sauce.
Store leftovers in the fridge for up to 4 days. If you’re reheating the entire dish, reheat in the oven until bubbly. If you’re reheating a single portion, you can reheat it in the microwave.
It’s not recommended to freeze, as it can change the texture of the cauliflower and the sweetpotato cheese sauce. For best results, enjoy fresh or store in the fridge up to a few days before serving.
Why You’ll Love This Recipe
As a dietitian, I love this recipe for many reasons – and I think you will too!
- Unique way to use sweetpotatoes (your guests will be begging for the recipe!)
- Packs in 12 grams of protein per serving – great for rounding out any meal
- Excellent source of Vitamin A (thanks to those sweetpotatoes) which is key for eye and immune health
- Excellent source of calcium, Vitamin C, and Vitamin B12
- Great way to eat extra veggies – because who doesn’t love something covered in a cheesy sauce?
More Fall Sweetpotato Recipes
If you’re looking for more seasonal recipes featuring sweetpotatoes, be sure to give one of these a try:
- Marry me beans & sweetpotatoes
- Savory sweetpotato ricotta breakfast bowls
- North Carolina sweetpotato cake
- Sweetpotato harvest salad
- Instant pot sweetpotato crumble
I hope you enjoy this recipe! If you get a chance to try it, feel free to leave a recipe rating or comment below.
Sweetpotato Cauliflower Gratin
Ingredients
- 2 medium heads cauliflower, cut into florets (about 3 pounds)
- 2 medium North Carolina sweetpotatoes, peeled and chopped
- 2 tablespoons butter
- 2 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 2 cups 1% milk
- ½ teaspoon salt
- ¼ teaspoon smoked paprika
- ¼ teaspoon black pepper
- ⅛ teaspoon ground nutmeg
- 1 cup shredded cheddar cheese, divided
- ½ cup fresh shredded parmesan cheese, divided
- ¼ cup breadcrumbs
- 1 tablespoon olive oil
Instructions
- Preheat the oven to 375 degrees F. Set aside a casserole dish.
- Fill a medium-large pot about halfway with water. Bring to a boil, then add the cauliflower florets. Boil for 5 minutes, then use a slotted spoon to remove the cauliflower and set aside in a large bowl.
- Add the sweetpotatoes to the same pot with the water, adding more if needed. Boil for 10 minutes, or until tender.
- Drain sweetpotatoes and place them in a bowl of a mini food processor. Let cool for a few minutes, then puree until smooth, leaving the spout open on the food processor bowl.
- In the same pot previously used, heat the butter over medium heat. Add the garlic and cook for a minute, until fragrant. Add the flour and cook for another minute, stirring often, until it starts to turn a light golden color.
- Pour in the milk little by little, stirring after each addition, until all the milk has been added and is well combined.
- Add the salt, paprika, pepper, nutmeg, and pureed sweetpotatoes. Reduce heat to medium-low and cook for 2-3 minutes, stirring often, until well combined.
- Add ½ cup of the cheddar cheese and ¼ cup of the parmesan cheese to the sauce mixture. Cook for another 1-2 minutes, stirring often, until well combined.
- Pour a layer of the cheese sauce in the bottom of the casserole dish. Take the bowl of cauliflower and dab it with paper towels to remove any excess moisture that is on the vegetables. Add the cauliflower to the casserole dish, then pour the remaining cheese sauce on top. Sprinkle with the remaining ½ cup of cheddar cheese, the remaining ¼ cup of parmesan cheese, and the breadcrumbs, then drizzle with the olive oil.
- Bake at 375 degrees F for 25-35 minutes, until the mixture is bubbly and the breadcrumbs are golden brown on top. Let cool for at least 15 minutes for sauce to fully thicken, then serve warm and enjoy.
Notes
- It’s important to leave the spout open on the food processor when pureeing so that the heat of the cooked sweetpotatoes doesn’t pressurize the container.
- If you don’t have a mini food processor, you can alternatively just mash the sweetpotatoes well in a bowl.
- This recipe makes approximately eight 1-cup servings. The total yield may vary based on the size of the heads of cauliflower used, so consider that an estimate.
Nutrition
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