Whether it’s a holiday dinner or a busy weeknight, this broccoli au gratin recipe delivers! It’s elegant, yet easy to make, and you can’t go wrong with broccoli and cheese!
If you’re a fan of potato au gratin, you’re going to love this broccoli version. It’s a delicious way to get in your green veggies and mix up the side dish routine.
Tender fresh broccoli is topped with a luxurious bechamel sauce with gruyere and parmesan cheese, topped with more cheese – because why not – and finished with a layer of crispy panko bread crumbs. Totally comforting, totally irresistible!
What is Au Gratin?
Gratin refers to a crispy top from either cheese or breadcrumbs. Typically made with potatoes, au gratins are vegetables tossed in a delicious cream sauce, also referred to as bechamel sauce. Cheese is added and other you have it, a vegetable au gratin!
Ingredients You’ll Need
There are two parts to this recipe: the sauce and the broccoli. This sauce is inspired by my scalloped potatoes recipe, so if you like this one, you should definitely give those a try next!
- Fresh Broccoli: fresh broccoli delivers the best texture and flavor in this recipe. You could use frozen, just be sure to see the tips below for best results.
- Yellow Onion and Garlic: these aromatics bring flavor to the cheese sauce.
- All-Purpose Flour: to thicken the sauce. To make it gluten-free, use gluten-free flour or cornstarch.
- Whole Milk: make sure it’s room temperature so it doesn’t break the sauce.
- Vegetable Stock: adds flavor and thins the sauce out a bit. Be sure to taste test before adding so you know how salty it is. That will determine how much salt you should add.
- Spices: of course salt and pepper to taste, a little white pepper for interest, nutmeg because it pairs so well with gruyere, and a little cayenne pepper for a super subtle kick.
- Gruyere Cheese: it’s nutty, rich, and creamy. It pairs so well with broccoli, too!
- Parmesan Cheese: use grated parmesan for best results, not shredded.
- Panko Breadcrumbs + Olive Oil: for the crispy topping!
A note about vegetarian cheese: if needed, find gruyere and parmesan cheeses that are specifically labeled vegetarian, kosher, or made with microbial enzymes. You can also substitute the gruyere with white cheddar or mozzarella.
How to Make Broccoli au Gratin
Prep the Broccoli
Make sure you wash the broccoli well, and dry it as best as you can.
Trim the broccoli into evenly sized florets. You can even use the stalk too, or save them for a broccoli salad.
Place them directly into the 8×8 or 9×9 casserole dish you’ll be using and set aside until they’re ready to be coated in cheese!
Make the Cheese Sauce
Technically, we’re making a bechamel sauce. Bechamel is a type of white sauce made with a roux (a mixture of butter and flour) and milk. It’s creamy and delicious!
I’m taking my version a step further and adding diced onion and garlic for flavor. They both work so well to flavor the sauce and add to the overall dish without extra steps.
Add the flour before the liquid so it has time to cook. This removes the raw taste. It also coats the flour in the fat from the butter which helps in creating a smooth sauce free of any lumps.
Whisk in vegetable stock until combined. Then, add in room temperature or warmed milk. Bring the sauce to a simmer, stirring frequently. Don’t let it boil!
You’ll know it’s ready when it’s slightly thickened, and it coats the back of a spoon without slipping right off.
Remove from heat and whisk in the cheeses. You may want to work in batches to make sure it’s melted through all the way. And remember, the cheese you shred yourself will melt much better than pre-shredded cheeses!
Combine and Bake!
Pour the cheese sauce over the broccoli in the pan, working it into nooks and crannies.
If you’d like (and why wouldn’t you?!) sprinkle on the remaining cheese across the top. Then, it’s time for the breadcrumbs!
Stir together the panko and olive oil in a small bowl. Feel free to use melted butter, too. Then, once they’re well coated, spread them evenly across the gratin.
Cover the pan with foil and bake for 15 minutes. Uncover, baking for an additional 5-10 minutes until the breadcrumbs are golden brown, the sauce is bubbly, and the broccoli tender.
What to Serve with Broccoli Gratin
Broccoli au gratin is a delectable vegetable side dish that pairs with just about any protein. If you’re a seafood eater, you’ll love it with baked salmon or firecracker shrimp. For meat eaters, you can’t go wrong with anything from steak, to chicken, to pork…you name it, it’s a classic side!
It can be a meal in itself, served with a nice green salad, too. Pair it with steamed carrots, roasted root vegetables, or roasted butternut squash. These hearty, starchy veggies balance out the cruciferous veggie.
Recipe Tips for Success
- Cut similarly sized broccoli florets. This ensures they all cook at the same rate. The smaller the florets, the less time they require while baking.
- Taste test the sauce before topping to make sure there is enough salt.
- Bake with foil until the end, so the breadcrumbs don’t burn.
- Turn on the broiler if the breadcrumbs aren’t crisp yet the broccoli is done.
- Remember, cook time my vary depending on the size of your florets!
Did you make this recipe? Please leave a star rating and review in the form below. I appreciate your feedback, and it helps others, too!
Get the Recipe Broccoli au Gratin
- 1.25 pounds heads of broccoli, cut into 1-inch florets (approximately 6 cups)
- 3 Tablespoons unsalted butter
- ½ cup yellow onion, diced
- 4 garlic cloves, minced
- 2 Tablespoons all-purpose flour
- ½ cup vegetable stock
- 1 ¼ cup whole milk, room temperature or warmed
- ½ teaspoon kosher salt, to taste
- ⅛ – ¼ teaspoon white pepper
- Black pepper, to taste
- 4 ounces gruyere cheese, shredded, divided
- ½ cup grated parmesan cheese, divided
- ⅛ teaspoon ground nutmeg, or pinch
- ⅛ teaspoon cayenne pepper
- Preheat oven to 425°F. Place the broccoli florets in an 8×8 skillet and set aside. In a small bowl, stir together 2 tablespoons olive oil and bread crumbs.
- In a large stockpot or sautee pan, melt butter over medium heat. Add onion and saute for 2-3 minutes, adding a pinch of salt to begin layering in the flavor. Add garlic and continue to saute for 1-2 minutes. Then stir in the flour and spices. Continue to stir for 1-2 minutes to ensure the flour does not burn.
- Whisk in the vegetable broth until combined, scraping the bottom of the pan as needed. Once combined, whisk in warm milk. Add any remaining salt as needed. Bring cream sauce to a simmer and continue to lightly simmer for 4-5 minutes, being careful it doesn't boil. Remove from heat.
- Stir in half of the gruyere (2 ounces) and 1/4 cup parmesan cheese. You may need to work in batches until melted and smoothed into sauce.
- Pour the cream sauce over the broccoli and top with the remaining shredded cheese. Top with the prepared breadcrumbs.
- Cover the pan with foil and bake for about 15 minutes. Remove the foil and bake for an additional 5-10 minutes until the bread crumbs are golden brown and the sauce bubbly; check the broccoli to make sure it’s tender, too. If needed, turn on the broiler to crisp up the breadcrumbs if the broccoli is already tender.
- Serve immediately. Store any leftovers in the fridge for up to 4 days. Reheat in the oven or microwave until warmed through. Enjoy!
- Gluten-Free: use gluten-free flour and breadcrumbs.
- Cook time will take longer if you use larger broccoli florets.
- Frozen Broccoli: thaw, and be sure to pat very dry before using.