Cauliflower Casserole Recipe

I just pulled this bubbling, golden beauty out of the oven, and the aroma of roasted garlic and toasted parmesan is absolutely filling my kitchen right now. There is honestly nothing more comforting than transforming a simple head of cauliflower into something so rich and decadent that it steals the spotlight from the main course.

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Prep Time 20

Cook Time 45

Servings: 8

Ingredients Method Notes

Ingredients

4 ½ tablespoons unsalted butter
I prefer using unsalted butter because it gives me total control over the sodium levels in the sauce ensuring it tastes rich without becoming salty.
2 cloves garlic
Fresh garlic is non-negotiable here; you want to press it yourself to release those potent aromatic oils that infuse the butter base instantly.
4 ½ tablespoons all-purpose flour
This is the structural backbone of your sauce thickening the liquid into a velvety consistency that coats the vegetable perfectly.
2 ½ cups milk 2% reduced fat
While you can use whole milk for decadence I find that 2% provides the perfect balance of creaminess without making the dish feel overly heavy or greasy.
1 ¼ cup grated parmesan cheese
Always grate your parmesan fresh from the block because pre-grated versions contain anti-caking agents that prevent the cheese from melting into a smooth cohesive sauce.
Salt
You will use this in stages both to season the blanching water for the cauliflower and to wake up the flavors in your creamy white sauce.
Black pepper
A pinch of freshly cracked black pepper cuts through the richness of the dairy and adds a subtle earthy heat that lingers on the palate.
½ cup panko breadcrumbs
Japanese-style panko crumbs are essential because they are larger and airier than traditional crumbs guaranteeing a topping that stays crunchy rather than getting soggy.
¼ teaspoon paprika
This spice isn't just for flavor; it adds a beautiful warm golden hue to your breadcrumb topping once it toasts in the oven.
3 pounds cauliflower florets
Look for firm white heads without blemish, or buy pre-cut florets to save time, ensuring they are cut into uniform bite-sized pieces for even cooking.
¼ teaspoon granulated onion
This dried aromatic adds a concentrated savory depth that permeates the casserole in a way that fresh onions sometimes miss in creamy sauces.
½ cup grated fontina cheese
Fontina is the secret star here offering a superior melting quality and a mild, nutty flavor that bridges the gap between the sharp parmesan and sweet cauliflower.
1 tablespoon chopped fresh parsley
This fresh herb provides a burst of color and a clean grassy finish that brightens up the heavy, cheesy flavors of the casserole.

Method

Start by preheating your oven to 375°F so it is fully up to temperature when you are ready to bake. While the oven warms, gather all your ingredients, chop the parsley, grate your cheeses, and have your baking dish ready on the counter. This "mise en place" approach ensures the cooking process flows smoothly without any panic.
Place a medium saucepan over medium heat and melt 2 ½ tablespoons of the butter until it is bubbling gently. Add the pressed garlic to the melted butter and stir it constantly for just a minute until it becomes incredibly fragrant but not browned. Sprinkle the flour over the butter and stir to create a thick paste, cooking for a minute to remove the raw flour taste.
Slowly pour the 2% milk into the roux while whisking continuously to prevent any lumps from forming in your base. Continue to cook this mixture over medium heat, whisking often, for about 5 to 6 minutes until it reaches a vigorous simmer and thickens. It should coat the back of a spoon nicely, resembling the consistency of heavy cream.
Remove the thickened sauce from the heat immediately to prevent it from scorching or separating. Whisk in your salt, pepper, and one cup of the grated parmesan cheese until the cheese is fully melted and the sauce is smooth. Set this pot aside in a warm spot so it stays fluid while you prepare the vegetable components.
In a small bowl, combine the panko breadcrumbs with the remaining ¼ cup of parmesan cheese and the paprika. Melt the remaining 2 tablespoons of butter and drizzle it over the crumb mixture, using a fork to toss everything together until evenly coated. This step ensures your topping browns evenly and achieves that perfect, audibly crunchy texture.
Bring a large pot of salted water to a rolling boil and carefully drop in your cauliflower florets. Cook them for only 4 to 5 minutes so they become slightly tender but still retain a firm "bite" or crispness in the center. Drain them very well in a colander, shaking off excess water to prevent a watery casserole sauce later.
Spread about one cup of your warm parmesan sauce across the bottom of your baking dish to create a flavorful bed. Arrange the blanched, drained cauliflower florets on top of the sauce and season them evenly with the granulated onion. Pour the remaining sauce over the top, using a spatula to ensure every single floret gets a coating of the liquid gold.
Sprinkle the grated fontina cheese over the sauced cauliflower, followed immediately by your prepared panko breadcrumb mixture. Place the dish in the center of your preheated oven and bake for 25 to 30 minutes. You are looking for the sauce to be bubbling vigorously at the edges and the top to be a deep golden brown.
Once baked, remove the casserole from the oven and let it sit for about 5 to 10 minutes to set. This resting period allows the sauce to thicken slightly, making it easier to serve clean scoops. Sprinkle the chopped fresh parsley over the top for a pop of freshness and serve it while warm.

Notes

Dry the Cauliflower Thoroughly: In my experience, the biggest mistake people make is not drying the vegetable enough; I always let the cauliflower sit in the colander for a few extra minutes or even pat it with paper towels to ensure the sauce doesn't get watered down.
Grate Your Own Cheese: I cannot stress this enough—pre-shredded cheese contains cellulose which stops it from clumping in the bag but creates a grainy sauce; buying a block of fontina and parmesan and grating it yourself changes the texture from good to gourmet.
Don't Overcook the Blanch: I suggest checking the cauliflower at the 3-minute mark during blanching; you want it to be "al dente" because it will continue to cook in the oven, and nobody likes mushy cauliflower in a casserole.
Broil for a Finish: If the cooking time is up but your topping isn't quite as brown as you like, I recommend switching the oven to broil for the last 1-2 minutes, but watch it like a hawk so it doesn't burn.