Easy Cheesy Broccoli Au Gratin Recipe

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This creamy and cheesy Broccoli Au Gratin Recipe is made with fresh and tender broccoli florets, sharp white cheddar, nutty gruyere cheese, and seasoned with minced garlic and fragrant herbs. The perfect holiday side dish.

While this broccoli gratin is a holiday and potluck staple, it’s actually a great recipe for a weeknight meal. Quick, simple, tastes amazing! Kids love it!

If you’re a fan of this broccoli au gratin, you should try some more of my easy and delicious recipes, like this Chile Relleno Casserole, Classic Green Bean Casserole (no canned soup), Zucchini Ground Beef Casserole. My Wild Rice Supreme is also worth checking out—it can even be made gluten-free and vegetarian!

Broccoli au gratin is much like the classic potato gratin with a simple béchamel sauce. It’s an excellent low carb Thanksgiving side, a healthier Christmas side dish or is a fantastic side for Easter ham dinner, but goes great with turkey too!

“We devoured it. My son ate later and I said, how do you like the broccoli? He said: very, very incredible. 10/10 would recommend.” Chellie ~ Reader Review

Simple Ingredients

Ingredients, directions and nutritional information in the printable recipe card at the end of the post.

Au Gratin Recipe

• Broccoli Florets |  I always recommend using organic and fresh broccoli, but if you’re in a pinch, you can use frozen broccoli.
• Butter | Whether you use salted or unsalted butter is up to your personal preference. You’ll use butter to create the irresistible cheese sauce.
• Flour | You’ll need some all-purpose flour to make a thick and creamy sauce. You may also use a gluten-free product if desired.
• Garlic, Thyme & Rosemary | Classic herbs perfectly compliment this creamy au gratin.
• Half and Half | For a rich and creamy cheese sauce, use half and half. You may also use whole milk but expect the sauce to be a little less rich.
• Kosher salt and pepper | As with many recipes, you’ll sprinkle in some salt and pepper to taste. You may use white or black pepper, depending on your preference.
• Nutmeg | Warm nutmeg enhances the flavor in the tasty cheeses of this sauce.
• White Cheddar Cheese | You’ll grate a block of sharp white cheddar cheese to add a bold flavor to the sauce of this casserole.
• Gruyere Cheese | Grated gruyere cheese lends a creamier and nuttier taste to balance out the sharp notes of the cheddar.

Optional Panko Topping

• Panko Bread crumbs | Panko bread crumbs have a nice and crisp texture, unlike any other bread crumb. However, if you prefer using a more common bread crumb or even crushed Ritz crackers, go for it!
• Butter | A little melted butter acts like the glue to hold together the parmesan and panko for a delicious topping.
• Parmesan Cheese | Freshly grated parmesan cheese blends beautifully with the panko crumbs and adds some sharp flavor.

How to Make this Low Carb Broccoli Au Gratin Recipe

Step 1 | Prep and Preheat

Preheat the oven to 375 degrees F and spray an 8×8 baking dish with cooking spray or rub with some olive oil or a little butter (mmm). You may also use a gratin dish or double the recipe and make it in a 9×13 inch dish. The choice is yours! 

Or if you prefer it not as cheesy of a dish, double the broccoli, keep the cheesy sauce the same and make in a 9 x 13 inch dish.

Cut up the head of broccoli into bite-sized pieces, but you want them to be a rather large broccoli floret.

Step 2 | Begin the White Sauce

In a medium saucepan over medium heat, melt the butter and stir in the minced garlic. Continue stirring just until the garlic is fragrant, which will take about a minute. Then sprinkle flour and whisk for about 5-6 minutes until thick and golden. 

Next, slowly pour in the half and half (or whole milk) while whisking constantly until the mixture is thick and coats the back of a spoon. 

Step 3 | Steam the Broccoli

Meanwhile, steam the broccoli by bringing a large pot with about 1-2 inches of water to a simmer and adding a large steamer basket or insert. Toss in the broccoli florets and cover to steam for about 5 minutes.

For now, you’ll only be partially cooking the broccoli. You’ll know it is just right when the florets are bright green with a slight crunch when pierced with a fork. Remove the broccoli from the pot and strain in a colander. 

Step 4 | Add the Cheeses and Seasonings

Add nutmeg, salt and pepper to your liking. Next, toss in some chopped rosemary and thyme, if desired. Then, stir or whisk in the shredded cheeses half a cup a time.

Continue stirring over low heat and adding the cheeses until the sauce is melted and smooth. Set aside ¼ – ½ cup of gruyere to sprinkle on top of the casserole.

Step 5 | Assemble Casserole

Place steamed broccoli in the prepared baking dish, then pour cheese sauce over the top of the broccoli as evenly as possible. Sprinkle with the reserved grated cheese and bake for about 20 to 25 minutes. Then, it’s time to serve up this cheesy goodness!

Optional Panko Topping

If you’d like, add a crisp, buttery topping! In a small bowl, combine the melted butter, breadcrumbs (or crackers), and parmesan cheese or a little more gruyere. 

Sprinkle bread crumb topping over the top of the broccoli au gratin. If desired, sprinkle with the last of the remaining cheese. 

Finally, bake at 375 degrees for 20-25 minutes until the gratin is bubbly and the crunchy breadcrumbs are golden brown. Then, you’re ready to serve!

Variations & Substitutions

This versatile recipe is perfect for customization! Here are some creative ideas to get you started:

• Use half broccoli and half cauliflower for a little more variety.
• Replace the gruyere cheese with your favorite shredded block cheese! Swiss cheese, parmesan cheese, sharp white cheddar would all be delicious.
• Crisp up 3-4 thick slices of bacon and toss those with the broccoli before covering with sauce.
• Add caramelized onions to the broccoli mixture.

Gluten-Free Broccoli Au Gratin | Just use a gluten-free flour alternative and ensure the dried spices you buy are labeled as gluten-free and if using panko, purchase a gluten-free panko.

Storage & Travel Tips

Store leftover baked broccoli au gratin in a covered dish in the fridge for 3-5 days.

Freeze | Broccoli au gratin will freeze well, allow to cool completely on the counter before freezing, then cover with plastic wrap and again with foil, freeze up to 3 months.

How to transport Broccoli Au Gratin recipe

When it’s hot from the oven, slip the broccoli au gratin into an insulated casserole carrier if possible. Cover tightly with foil and lay a tea towel over the top. This should keep the meal nice and warm for travel.

If your journey to Grandma’s house was a little too far, pop it back in the oven at 350 degrees for 10-15 minutes, removing the cover for the last 5 minutes or so.

Frequently Asked Questions

Serving Suggestions for Broccoli Au Gratin

You can serve this versatile recipe as a delicious side dish or as the main entrée. Try this cheesy casserole with these entrees.

1. Honeybaked Ham
2. Best Instant Pot Turkey Breast Recipe
3. Simple Tender Tasty Turkey
4. Italian Braised Short Ribs
5. Turkey Divan Recipe (or chicken)

More Holiday Side Dishes

• Smoked Mac and Cheese
• Rice Pilaf with Dried Cranberries and Slivered Almonds
• Brown Sugar Pecan Roasted Sweet Potatoes
• Maple Bacon Carrots
• Holiday Praline Yams (Sweet Potatoes)
• Easy Corn Casserole without Jiffy
• Southern-Style Green Beans
• Baked Asparagus with Bacon and Parmesan Cheese
• Cheesy Funeral Potatoes
• Cranberry Fluff or Cranberry Relish

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