This cauliflower gratin is a cheesy and delicious vegetarian side dish with tender cauliflower florets baked in a creamy cheese sauce with garlic, onions, and seasonings. I top my gratin with crispy toasted almonds instead of breadcrumbs. It’s the best!
This cauliflower gratin is my carb-conscious alternative to sweet potato gratin and potato casserole. It’s creamy and decadent, yet still light and packed with veggies!
As someone who’s firmly pro-cauliflower, I’ll eat it mashed, grilled, baked, and even as a steak. And if there was ever a time to swan-dive into a side dish, it would be when I’m making cauliflower gratin. This easy recipe has tender cauliflower florets drenched in cheese sauce and baked until it’s golden and bubbly, topped with crispy toasted almonds. This might not be a traditional potato gratin, but it’s a delicious and low-carb version of the classic.
Why I Love This Cauliflower Gratin Recipe
- Loaded with cauliflower. The cauliflower florets soak up all the flavor in this cheesy gratin perfectly. You won’t even miss the potatoes!
- A lighter way to gratin. Aside from skipping the potatoes, my cauliflower gratin recipe uses a blend of half-and-half and milk instead of heavy cream, and chopped almonds instead of breadcrumbs for the topping. It has all the creaminess and crunch that I love, made lighter.
- Make-ahead friendly. This cauliflower gratin is easy to whip together on the stovetop and assemble in a baking dish the night before. I love making it as a holiday side that I can pop into the oven on the day.
What Does “Gratin” Mean in Cooking?
Something cooked au gratin, or gratinée, refers to any dish baked beneath a topping of cheese or breadcrumbs mixed with butter. Most recipes au gratin are assembled in a casserole dish. I always think of a gratin as a side dish, however, while a casserole, in most cases, can be a main.
What You’ll Need
This cauliflower gratin starts with a béchamel sauce. This is just a fancy-sounding name for a white sauce made from flour, butter, and milk. I’ll go over this and the rest of the ingredients below. You’ll find the full, printable ingredients list with amounts in the recipe card after the post.
- Butter and Flour – You’ll cook these together to make a roux for the base of the sauce.
- Milk – This can be whole milk, 2%, or your choice of dairy-free milk alternative. I also include half-and-half in my recipe, but you can use heavy cream or milk depending on how rich you like your sauce.
- Cheese – I shred up sharp Manchego cheese, but you can use Gouda, Gruyère, or good ol’ cheddar cheese. Feel free to use a blend of different cheeses! Make sure to use freshly grated cheese for the smoothest cheese sauce.
- Herbs – Dried thyme and Italian seasoning are my favorites. You can season your gratin sauce with another blend, like Herbes de Provence, or get creative with dried or fresh herbs.
- Seasonings – In addition to salt and pepper, I use chili powder and nutmeg to season the cheese sauce. You can adapt the seasonings to suit your tastes.
- Cauliflower – You’ll need a sizeable head of cauliflower, rinsed and chopped into florets. Look for cauliflower that’s fresh and firm, without any discoloring.
- Onion and Garlic – Freshly minced garlic, and diced yellow onion or shallot.
- Garnishes – Paprika and chopped almonds to garnish the finished gratin. You can replace the almonds with traditional breadcrumbs if you prefer.
How to Make Cauliflower Gratin
Gather your ingredients, and let’s make a creamy, cheesy cauliflower gratin that might just steal the show at Christmas dinner. Follow these easy steps:
- Make the cheese sauce. You’ll start by cooking off flour in melted butter to make a roux. Next, whisk in milk and half-and-half and let that simmer and thicken. Finally, take the sauce off the heat and stir in your grated cheese and seasonings.
- Cook the cauliflower. Meanwhile, par-boil the cauliflower florets. Afterward, sauté the cauliflower with the onions, butter, and garlic.
- Assemble. Spread the cauliflower into a casserole dish, and pour the cheese sauce evenly over top. Sprinkle the top with chopped almonds and paprika.
- Bake. Bake this cauliflower gratin at 400ºF for 20 minutes until it’s bubbly at the edges and golden on top. Give it a few minutes to rest after baking, and serve!
Make-Ahead
Cauliflower au gratin is a great side dish to prepare in advance. Assemble the cheese sauce and cauliflower in the baking dish, and then cover and refrigerate it overnight. The following day, take out the gratin and let it come to room temperature before baking as directed. Easy!
Tips and Variations
- Don’t overboil the cauliflower. Overcooked cauliflower tends to be mushy, and since you’ll be baking it after boiling, be careful that it doesn’t boil too long. You want the florets to be fork-tender, but still a bit crisp.
- Grate the cheese fresh. No matter which kind of cheese you use, make sure to shred it fresh from the block. Pre-shredded cheese contains anti-caking agents that keep it from clumping, and those same ingredients keep it from melting smoothly.
- Add the cheese off the heat. Be sure to take the béchamel sauce off the heat before you stir in the grated cheese. This avoids clumping and separating, which can happen when dairy gets overheated. Let the cheese melt slowly for best results.
- Make it meaty. If you’re not keeping this recipe vegetarian, add cooked crumbled bacon or diced ham (try leftover glazed ham) for extra protein.
Storing and Reheating Leftovers
- Refrigerate. The baked cauliflower gratin can be refrigerated airtight for up to 3 days.
- Reheat. I recommend reheating gratin under foil in a 350ºF oven, or you can warm individual servings in the microwave until hot throughout.
- Freeze. To freeze leftovers, wrap the cooled cauliflower gratin in a double layer of plastic wrap or foil and freeze for up to 3 months. Thaw the gratin in the fridge before reheating.
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Prep. Preheat the oven to 400ºF.
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Make a roux. Melt 2 tablespoons of butter in a skillet. Add the flour and whisk over medium-high heat for 1 minute. Add the milk and the half-and-half and cook, whisking constantly, until thickened, about 5 minutes.
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Make it cheesy. Remove the skillet from heat and whisk in the cheese. Whisk in the thyme, Italian seasoning, salt, pepper, chili powder, and nutmeg. Set aside and keep warm.
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Cook the cauliflower. In a large skillet, bring 1/2 inch of salted water to a boil. Add the cauliflower florets, cover, and cook over high heat for 5 minutes. Afterward, drain the cauliflower in a colander.
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Sauté. Melt the remaining butter in a skillet. Add the onion and cook over medium-high heat for 3 minutes. Stir in the minced garlic and continue to cook for 1 minute, or until fragrant. Add the prepared cauliflower florets to the skillet and cook, stirring frequently, for 2 minutes.
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Assemble. Transfer the cauliflower mixture to a 2-quart baking dish. Spread the prepared cheese sauce on top. Sprinkle the top with the chopped almonds and paprika.
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Bake. Bake the gratin in the oven for 20 minutes, or until bubbling and browned on top. Let stand for 10 minutes before serving.
- Make-ahead: The gratin can be prepared ahead of time! Prepare the cheese sauce and the cauliflower, assemble it in a baking dish, and refrigerate over night. When ready, bring it to room temperature before baking.
- Inspired by Food & Wine.
Calories: 256kcal | Carbohydrates: 16g | Protein: 10g | Fat: 17g | Saturated Fat: 10g | Cholesterol: 45mg | Sodium: 241mg | Potassium: 631mg | Fiber: 3g | Sugar: 7g | Vitamin A: 450IU | Vitamin C: 74.8mg | Calcium: 310mg | Iron: 1.1mg
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.