Cauliflower Au Gratin Recipe

Cauliflower Au Gratin in a baking dish with a spoon on the side.

This Cauliflower Au Gratin is a delightful cheesy bake that elevates cauliflower to a golden and crispy treat. Whether you make it a part of your Thanksgiving menu or serve it as a side dish to accompany your favorite steak and chicken recipes, it is guaranteed to impress.

Course Side Dish

Cuisine American

Diet Vegetarian

Prep Time 20

Cook Time 30

Total Time 50

Servings Servings

Calories 353kcal

Author Aysegul Sanford

Ingredients

2 heads cauliflower cut into bite-sized florets (total of 3 pounds of florets) *
Kosher Salt
3 tablespoons unsalted butter
3 cloves garlic finely minced or pressed
3 tablespoons all-purpose flour
2 ¼ cups whole milk
1 ½ teaspoons Kosher salt
¾ teaspoon ground black pepper
Pinch of nutmeg
1 ¾ cups Gruyere cheese shredded, divided - 6 ounces - Swiss or Cheddar cheese would also work
¾ cup grated Parmesan cheese divided
½ cup panko breadcrumbs
2 tablespoons fresh parsley chopped

Instructions

Preheat the oven to 400 degrees F.
Place the cauliflower florets in the stock pot and a few teaspoons of salt and cover with water.
Cover the pot and bring it to a boil over high heat, then reduce to medium heat and cook for 4-5 minutes until the cauliflower is softened but still firm when pierced with a fork or knife.
Drain and shake to remove any excess water. Set aside.
Meanwhile, melt the butter in a large skillet* over medium heat. Add the garlic and saute for 30 seconds to soften.
Add the flour. Whisk constantly until the flour is cooked (but not browned) for 1 minute.
While whisking constantly, pour in the milk and increase the heat to medium-high. Bring it to a boil and cook for 2-3 minutes or until thickened but still smooth.
Remove from the heat and add the Kosher salt, ground pepper, nutmeg, 1 cup of Gruyere cheese, and 1/4 cup of Parmesan cheese. Whisk to combine until the cheese melts and the mixture is smooth.
Add the cauliflower florets and toss to combine.
Place the mixture into the baking dish and smooth it out evenly.
Sprinkle the top of the mixture with the remaining Gruyere cheese, Parmesan cheese and panko bread crumbs.
Bake for 25-30 minutes until the cheese is bubbling and the top is browned. The cauliflower should be tender when pierced with a fork or knife.
Cool for 5 minutes, garnish with parsley if desired and serve.

Notes

Yields: This recipe makes a 9 by 13 casserole full of cauliflower gratin, which is ideal for serving as a side dish for 6 (generous portions.) The nutritional values below are per serving.
Cauliflower florets: The total weight of the cauliflower (3 pounds) is in reference to the cauliflower florets, not the whole head of cauliflower. During our recipe testing, we found the stalks weigh about 1 pound each per head, so pick up a 2-pound and 3-pound cauliflower head to get 3 pounds of florets in total.
Use a large enough skillet to mix everything together: I used a 12-inch skillet (affiliate link), which was large enough to make the cheese sauce, and tossed all the cauliflower so that each floret was coated with the sauce.
Make Ahead: You can make this dish a day in advance. Simply follow the recipe until you place the cheese and cauliflower mixture into the casserole dish (until step 11.) Bring to room temperature and cover well. Keep it in the fridge until you are ready to bake. When ready, follow the recipe as written and bake.
Storage: You can store the leftovers of this cauliflower casserole (after they come to room temperature) in an airtight container for up to 3 days in the fridge.

Nutrition