Broccoli Gratin

 Broccoli Gratin is a delicious side dish featuring roasted broccoli in a creamy cheese sauce topped with crispy chopped bacon. It’s a great-tasting way to ensure you’re getting your veggies in!

Cheese makes everything taste better, even broccoli! So, of course, I have cheese in my Broccoli Soup and a good recipe for Broccoli Salad. And that does not change for this best Broccoli Gratin.

What is a gratin?

I did a little research on the difference between casserole and gratin, also known as “au gratin,” as in Potatoes Au Gratin. I was surprised to find that the definition of a “gratin” is pretty fluid and, thus, hard to define. 

Generally, a gratin is usually baked in a shallow dish (sometimes called an “au gratin dish”), has a crust on top made from either cheese or bread crumbs, and is usually a side dish. A casserole, on the other hand, is generally a baked dish that stands alone as a meal. 

Ingredients for Broccoli Au Gratin

This broccoli recipe combines tender broccoli florets with a handful of simple ingredients to make a flavorful, cheesy sauce. Here’s what you’ll need:

• 5 cups of fresh broccoli, cut or torn into small florets (or bite-sized pieces)
• 3 tablespoons of olive oil​
• Salt and freshly ground black pepper
• 6 slices of bacon, cooked and chopped into pieces
• 1 1/3 cups shredded Parmesan cheese (divided)
• 1 cup of heavy cream
• 2 teaspoons dried thyme

How to make Broccoli Gratin

This au gratin recipe is ready to serve with dinner in about 45 minutes!

1. Preheat the oven to 400 degrees F. While it heats, cook and chop your bacon.
2. Place broccoli florets on a baking sheet. Drizzle olive oil over them and sprinkle salt and pepper to taste. Toss to coat.
3. Bake for 15 minutes, stirring occasionally, so smaller pieces don’t burn. When it’s done, remove the sheet pan from the oven and let the broccoli cool slightly.
4. In a large bowl, combine the broccoli with 1 cup of Parmesan cheese, heavy cream, thyme, and bacon pieces. Stir to coat.
5. Place the broccoli mixture into a baking dish prepared with nonstick cooking spray. Sprinkle the remaining cheese on top of the broccoli. Bake for 15 minutes or until the gratin is bubbly and golden brown on top. 
6. Remove the dish from the oven and let stand for several minutes before serving.

You’ll love this cheesy broccoli casserole!

Recipe Variations

• Squeeze fresh lemon juice over the broccoli before roasting for a light citrusy flavor.
• Add crunchy breadcrumbs mixed with melted butter to the top of the broccoli for added texture
• Mix in 1 teaspoon of garlic powder to the cheesy white sauce for a roasted garlic flavor.
• Use cheddar cheese instead of Parmesan cheese on top of the gratin.

FAQs

Can I use frozen broccoli in this broccoli dish?

Yes, frozen broccoli will work just fine. Be sure to let it thaw before using it in the recipe so you don’t have too much added moisture.

How do I store leftover Broccoli Gratin?

This dish will keep well in the refrigerator for 3-4 days. Cover the dish tightly with aluminum foil and store the covered dish in the fridge. Or transfer the contents to an airtight container.

Can I make this easy broccoli baked dish ahead of time?

Yes, you can bake this and freeze it to eat later. 

Follow the recipe as directed, then let it cool completely. Cover tightly with a layer of plastic wrap and another layer of aluminum foil, then store in the freezer. It will keep for up to a month.

To thaw, place the casserole dish in the refrigerator overnight. Heat it in a 350-degree oven for 20 minutes or until warm through.

What should I serve with Broccoli Gratin?

Broccoli Gratin is a great broccoli side dish that goes with just about any main dish. Here are some of my favorites:

• Honey Mustard Pretzel Chicken– the tangy sweetness with the crunchy pretzels makes this chicken dish spectacular!
• BBQ Chicken Burgers– pop these on the grill for a healthier burger!
• Cinnamon Balsamic Pork Tenderloin– this juicy pork dish is so flavorful you’ll want to make it often!
• Black Bean Burgers– a great recipe for a vegetarian burger option!
• Sweet Ginger and Soy Salmon– one of my favorite ways to enjoy salmon!

More Veggie Side Dishes

Up that vegetable intake with these delicious side dishes!

This easy side dish of Honey Mustard Brussels Sprouts might just convert the Brussels sprouts haters into lovers. Roasted in olive oil and then tossed with an easy tangy sauce, these Brussels sprouts will make a regular appearance on your dinner menu.

Mashed Butternut Squash brings your dinner to a whole new level when it’s combined with goat cheese and browned butter! This delicious recipe is perfect for a holiday meal or Sunday dinner!

This Mexican Corn Salad is tossed in a citrusy cumin lime vinaigrette! It’s the perfect light and refreshing side.

Root Vegetable Gratin is a flexible dish using your favorite root veggies in a creamy sauce with gruyere and Parmesan cheese. Think beets, parsnips, carrots, etc. Whatever you use, you’ll love how it tastes!

This post was originally published March 15, 2018. It has been updated in format and with photos on March 26, 2025.