When I need to add a vegetable to my holiday table or Thanksgiving dinner but want to dress it up so all my guests can’t get enough, I turn to this easy cauliflower gratin. Simply boil cauliflower florets, make an easy, creamy cheese sauce, and top with toasted breadcrumbs. Trust me, even the “veggie-haters” in your life will be wanting more and more of this cheese cauliflower bake!
The cheese sauce is what makes this casserole so special. Technically called a mornay sauce, it is basically béchamel sauce with cheese added to it. I have some substitutes for the Gruyere cheese called for in the recipe, which work well in a pinch, but the best flavor comes from Gruyere, so I highly recommend it. For more holiday casseroles, try my easy squash casserole recipe, classic green bean casserole, and broccoli casserole recipe.
What You Need to Make this Recipe
Cauliflower — you need a head of cauliflower cut into florets. Choose a bigger head of cauliflower (you need 3 pounds of florets!) that is firm with no soft or brown spots.
Butter — butter is an important part of the rich cheese sauce, and you also use it to toast the bread crumbs. Olive oil isn’t a good substitute for this recipe.
Flour — regular all-purpose flour is all you need. If you want to make this dish gluten-free, just use your favorite gluten-free all-purpose flour.
Milk — I use whole milk, but you could swap it for 2% milk if you like, or use half and half for a richer sauce.
Cheese — to make the mornay sauce, you’ll need to grate Gruyere and parmesan cheese. Instead of gruyere cheese, you can use another melty cheese like American Swiss cheese, sharp cheddar cheese, fontina cheese, or gouda cheese, but the flavor will be different.
Spices — black pepper and nutmeg add warmth and cozy flavor to the cauliflower cheese.
Bread crumbs — bread crumbs form a crunchy topping for the cauliflower bake. If you’re gluten-free, use gluten-free bread crumbs or gluten-free panko breadcrumbs.
How to Make Cauliflower Gratin
1. Add the cauliflower florets to a large pot of generously salted boiling water. Boil for about 10 minutes or just until fork tender. The cauliflower should still be firm. Drain well and set aside for now.
2. Make the cheese sauce in a medium saucepan. Melt butter over medium heat, then add the all-purpose flour and cook, stirring constantly, for 2 minutes.
3. Slowly whisk in the warmed milk until smooth. Bring the mixture to a boil while whisking. Then remove the saucepan from the heat.
4. Stir in 1 cup shredded gruyere cheese and grated parmesan cheese. Stir until the cheese has melted and the sauce is smooth. Add the black pepper, grated nutmeg, and salt to taste.
5. Spoon about ½ cup of cheese sauce into a casserole dish and spread it so it covers the bottom of the dish. Top with the drained cooked cauliflower.
6. Pour the remaining sauce over the cauliflower.
7. Sprinkle the rest of the shredded gruyere cheese over the top. Bake the cauliflower casserole for 20 minutes in an oven preheated to 375°F.
8. While the cauliflower au gratin is in the oven, toast the breadcrumbs. Melt 2 tablespoons of butter in a small skillet and then add the breadcrumbs. Cook, stirring frequently, until the crumbs start to toast and brown. Remove from the heat. After the cauliflower cheese bake has been in the oven for 20 minutes, carefully remove it from the oven and sprinkle the breadcrumbs on top. Pop it back into the oven until the top starts to brown and the filling is bubbly. This will only take about 5 minutes. Allow it to cool for 15 minutes before serving to allow the sauce to thicken up. Enjoy!
Pro Tips for Making this Recipe
- Don’t overcook the cauliflower, and drain it well. Boil the cauliflower just until it is fork-tender but still has some firmness to it. It needs to still have a bit of bite when you bake it, or it will turn into watery mush. When draining it, I like to use a colander and let the cauliflower sit for a few minutes to remove as much water as possible.
- Shred the cheese yourself instead of buying the pre-shredded kind. Pre-shredded cheese has anti-clumping agents added to it, so it isn’t as melty and gooey.
- Use freshly grated nutmeg if possible. Freshly grated nutmeg has a far superior flavor to pre-grated nutmeg in this cauliflower au gratin recipe.
- Add more flavor to the mornay sauce. Grated garlic cloves, garlic powder, or fresh chopped herbs would be a nice addition to the creamy cheese sauce.
- To make fresh breadcrumbs: Tear one or two slices of bread (I love crusty sourdough!) and pulse in a food processor until finely chopped. You can also finely chop it with a sharp knife. If you don’t have fresh bread, panko bread crumbs can also be used.
Frequently Asked Questions
Yes, you can make it ahead of time! Prepare the casserole as directed but don’t bake it. Once you sprinkle the cheese on top, allow it to cool, cover it tightly in plastic wrap, and refrigerate for up to 48 hours. When you’re ready, uncover and bake it as directed, toast the breadcrumbs, sprinkle them on top after 20 minutes, and then bake an additional 5 or so minutes until golden brown and bubbly.
Cauliflower gratin is a fantastic lighter holiday side next to an entree like easy turkey meatloaf, Thanksgiving roasted turkey, or oven-roasted chicken. I like to pair it with a hearty roasted vegetable salad or crunchy shaved Brussels sprout salad.
Once the cheesy cauliflower bake has cooled to room temperature, you can either cover the baking dish well in plastic wrap and refrigerate, or transfer it to an airtight container and refrigerate. It will keep for up to 5 days.
While you can technically freeze this cauliflower gratin recipe in a freezer-safe container, I don’t recommend it. The texture of both the cheese sauce and the cauliflower will be compromised in the freezer.
If you love this recipe try these out!
If you’ve tried this cauliflower gratin recipe, then don’t forget to rate the recipe and let me know how you got on in the comments below, I love hearing from you!
Cauliflower Gratin
Equipment
- Large Pot
- Suacepan
- 8×11″ or 2-quart baking dish
- Small skillet
Ingredients
- Salt to taste
- 1 large head cauliflower cut into florets (about 3 pounds/1.35kg)
- 5 tablespoons unsalted butter divided
- 2 tablespoons all-purpose flour
- 2 cups whole milk warmed
- 1¼ cups freshly shredded gruyere cheese divided (140g)
- ½ cup freshly grated parmesan cheese (40g)
- ½ teaspoon ground black pepper
- ¼ teaspoon grated nutmeg
- ½ cup fresh bread crumbs* (30g)
Instructions
- Preheat the oven to 375F.
- Bring a large pot of water to a boil over high heat. Generously salt. Add the cauliflower and cook for about 10 minutes or just until fork tender but still firm. Drain well.
- In a medium saucepan, melt 3 tablespoons of butter over medium heat. Add the flour and cook, stirring constantly, for 2 minutes. Whisk in the warmed milk until smooth. Bring to a boil while whisking. Remove from the heat.
- Stir in 1 cup gruyere cheese and parmesan cheese until smooth. Add the pepper, nutmeg, and salt to taste. Spread about ½ cup of the sauce on the bottom of an 8×11-inch baking dish. Top with the drained cauliflower. Pour the remaining sauce over the cauliflower and sprinkle with the remaining ¼ cup gruyere.
- Bake for 20 minutes.
- Meanwhile, melt the remaining 2 tablespoons of butter in a small skillet. Add the bread crumbs. Cook, stirring frequently, until starting to toast and turn brown. Remove from the heat. After 20 minutes of baking, sprinkle the bread crumbs over the baked cauliflower and continue baking until the top starts to brown and the filling is very bubbly, about 5 more minutes. Let cool for 15 minutes before serving.
Notes
- *To make fresh breadcrumbs: Tear one or two slices of bread (I love crusty sourdough!) and pulse in a food processor until finely chopped. You can also finely chop it with a sharp knife. If you don’t have fresh bread, panko bread crumbs can also be used.
- Don’t overcook the cauliflower, and drain it well. Boil the cauliflower just until it is fork-tender but still has some firmness to it. It needs to still have a bit of bite when you bake it, or it will turn into watery mush. When draining it, I like to use a colander and let the cauliflower sit for a few minutes to remove as much water as possible.
- Shred the cheese yourself instead of buying the pre-shredded kind. Pre-shredded cheese has anti-clumping agents added to it, so it isn’t as melty and gooey.
- Use freshly grated nutmeg if possible. Freshly grated nutmeg has a far superior flavor to pre-grated nutmeg in this cauliflower au gratin recipe.
- Add more flavor to the mornay sauce. Grated garlic cloves, garlic powder, or fresh chopped herbs would be a nice addition to the creamy cheese sauce.
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