Cauliflower au Gratin is a creamy veggie dish with roasted cauliflower in a rich cheesy sauce.
This cauliflower side dish is perfect alongside a roast dinner, and great with almost any cheese in your fridge!
What is Cauliflower au Gratin?
A gratin is a method of making a baked dish or casserole that’s covered in breadcrumbs and/or cheese and browned. We often think of Potatoes Au Gratin but it’s great for all kinds of vegetables including brussels sprouts, zucchini, spinach, and more!
In this recipe, the cauliflower is roasted (adding another layer of flavor) which keeps it from getting watery. The sauce is homemade but it’s easy to make and so rich!
Why You’ll Love This
- Super rich and super cheesy, it tastes amazing!
- Roasting cauliflower adds flavor while keeping it perfectly tender-crisp.
- The cheese sauce is great with any cheese that you have on hand.
- This dish is low carb and high in flavor.
- This cozy dish can be made ahead of time and baked before serving.
CAULIFLOWER: Choose a large head that is free of brown spots. Short on time? Use a fresh bag of pre-washed and pre-cut cauliflower.
This recipe does work with frozen cauliflower as well, be sure to drain it very well after cooking so the sauce doesn’t get watery.
SAUCE: This sauce uses milk in place of cream and cream cheese gives it an extra rich flavor and texture.
CHEESE: Sharp cheddar adds great flavor. I love to use a little bit of Gruyere or swiss cheese as well. If you’re not a fan of swiss cheese, use all cheddar or another type of cheese.
For a colorful vegetable au gratin, mix broccoli florets with the cauliflower or add a medley of veggies like zucchini, onions, or leeks to the roasting pan. Or add diced chunks of ham, cooked chicken, or bacon for a heartier main dish casserole.
How to Make Cauliflower au Gratin
- Roast: Roast seasoned cauliflower until tender.
- Make Sauce: While cauliflower is roasting, make a roux & whisk in milk (per the recipe below). Cook until bubbly.
- Add Cheese: Stir in remaining ingredients (except for ¼ cup cheddar cheese). Whisk & simmer until smooth.
- Bake: Combine the sauce with the roasted cauliflower and bake in a casserole dish.
Tips for Perfect Gratin
- Roasting the cauliflower keeps the sauce from getting watery. If you steam or boil (or use frozen) be sure to drain very well.
- Broccoli can be added to the cauliflower if desired.
- The sauce is very rich, ensure your cauliflower head is at least 7-8 cups.
- Remove the sauce from the heat before stirring in the cheese. If the cheese overheats or boils it can separate.
- The cheese on top can be replaced with buttery bread crumbs. Combine 1/3 cup breadcrumbs with 1 tablespoon melted butter and sprinkle over top before baking.
Keep leftover cauliflower au gratin in a covered container in the fridge for up to 4 days.
More Cheesy Sides
- Parmesan Roasted Brussels Sprouts
- Twice Baked Potatoes
- Quick Broccoli Rice
- Funeral Potatoes
- Baked Cauliflower Mac and Cheese
- Cheese Bread (Quick Bread)
Did your family love this Cauliflower au Gratin? Leave us a rating and a comment below!
Cauliflower au Gratin
- 8 cups cauliflower florets about 1 large head
- 2 tablespoons olive oil
- salt & pepper to taste
- 2 tablespoons butter
- 2 tablespoons all-purpose flour
- 2 cloves garlic minced, optional
- 1 cup milk
- 4 ounces cream cheese softened
- ¼ teaspoon salt or to taste
- ¼ teaspoon black pepper
- ½ teaspoon dry mustard powder
- 1 cup sharp cheddar cheese shredded & divided
- ½ cup Gruyere or swiss cheese shredded, or additional cheddar
- Preheat oven to 400°F.
- Rinse cauliflower and break into bite-sized florets. Toss with olive oil and salt and pepper to taste.
- Place on a baking sheet and roast 15-20 minutes or until tender.
- While cauliflower is roasting, melt butter (and garlic if using) in a saucepan until fragrant, about 30 seconds. Whisk in flour until smooth and let cook for 1 minute. Add milk a little at a time while whisking until smooth.
- Cook over medium heat until thick and bubbly. Stir in cream cheese, salt, black pepper, and mustard powder until smooth. Add in ¾ cup cheddar cheese and swiss cheese. Whisk until smooth.
- Toss cheese mixture with roasted cauliflower and place in a 2 qt casserole dish. Top with remaining cheese and bake 20-25 minutes or until heated through.
- Broil 1-2 minutes or until browned.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)