Broccoli Au Gratin with Fontina features creamy broccoli in a white cheese sauce with crispy, buttery bread crumbs! It's perfect for holidays or Sunday dinner!
If you're looking for a delicious broccoli side dish that's full of creamy, cheesy goodness, you're in the right place! You're going to want to save this broccoli au gratin recipe, folks.
It's perfect to include with your Thanksgiving dinner. And if your menu's already full, make a note to come back to this one when you want a broccoli gratin that will wow your family and guests.
But what's au gratin?
Sometimes called "gratinée," it refers to a dish topped with cheese or bread crumbs (or both, if you're like me). It's drizzled with butter and heated in the oven until golden brown with a crispy topping.
I've been making a version of this dish for nearly 25 years.
The original recipe used Swiss cheese for a classic Mornay sauce. But back in 2015, when I was tweaking the recipe, I forgot to buy Swiss cheese. I happened to have Fontina on hand and decided to go for it.
I'm so glad I did! It put a delicious, Italian twist on this dish and forever changed how I make this broccoli au gratin.
Broccoli: I always use fresh broccoli here and suspect frozen broccoli florets would turn out a bit soggy. However, for convenience, you can thaw frozen broccoli florets in the microwave and then cook them for a minute or so in the microwave until just tender. Dry them well before adding them to the casserole.
Milk: Whole milk thickens more quickly than 2% milk when making the white sauce (béchamel). I often use 2% to keep this recipe lighter, since whole milk produces a richer result. Use what you prefer.
And note, I don't add nutmeg to the béchamel sauce.
I'm not a fan of nutmeg in savory dishes. I'm sure that's some kind of culinary faux pas, but I'm just going to own it!
Fontina Cheese: Fontina is a rich and creamy, semisoft cheese with a mild, buttery, nutty flavor. It's made from cow's milk and originated in Italy. It melts beautifully!
It's one of the best things in life, but if you don’t have Fontina, you can use Swiss to make traditional Mornay sauce.
Bread Crumbs: Bread crumbs that you grate yourself have the best taste and texture here, but you can use storebought. Here’s how to make bread crumbs.
(I used homemade bread crumbs for the photos at the top and bottom of this post, while the collage photos show this dish made with store-bought bread crumbs. You can actually see the difference in texture.)
How to make broccoli gratin
See the card at the end of this post for the full recipe, but here's an overview.
Make the fontina cheese sauce
- Cook onions and garlic in melted butter.
- Add flour and whisk to combine. Cook it for a minute.
- Pour in the milk while whisking.
- Whisk constantly until the béchamel sauce is thickened. Add the shredded Fontina and seasonings and whisk to combine.
Cook, assemble and bake
- Briefly boil the broccoli until it is just tender.
- Cover the bottom of a 1 ½-quart baking pan (affiliate link) with some Fontina cheese sauce.
- Add the drained, cooked broccoli.
- Cover the broccoli with the rest of the creamy white sauce.
- Combine the bread crumbs with Parmesan and sprinkle them on top. Drizzle on melted butter.
- Bake until the top is browned and crispy.
- Slice the broccoli florets in half the long way to make the stems thinner. This helps the broccoli cook faster and turn out more tender.
- Make sure to pat the broccoli dry after boiling and draining it. This prevents a runny casserole.
- You can double this recipe for a 9x13 pan.
What to serve with it
This Italian broccoli casserole is great as a side for roasted Thanksgiving turkey and all the fixings! It’s also delicious with Italian Chicken Cutlets, Roasted Pork Loin or Steak Pinwheels with Bacon. For a vegetarian option, serve it with long-grain rice cooked like pasta.
Frequently asked questions
You can make the Fontina cheese sauce up to two days ahead. Refrigerate it in a sealed container, then reheat it on the stove before using it in this recipe.
I haven’t tried it and suspect the broccoli casserole would turn out soggy after being thawed. The sauce probably would separate as well.
This recipe calls for two ounces of Fontina, and it's often sold in a 5-ounce package. You can enjoy the extra Fontina with crackers or shred it into scrambled eggs or an omelet. It also would be great in a grilled cheese sandwich!
More recipes like this
- Pasta and Broccoli
- Italian Broccoli with Gremolata
- Skillet Green Beans with Bread Crumbs
- Baked Breaded Eggplant Slices
- Creamed Spinach-Artichoke Casserole
Broccoli Au Gratin with Fontina
- 1 ½ pounds fresh broccoli (one bunch)
- ½ cup finely chopped white onion (from about ¼ of a medium onion)
- 1 medium clove garlic
- 2 ounces Fontina cheese
- 2 Tablespoons salted butter
- 3 Tablespoons all-purpose flour
- 2 cups 2% or whole milk (see notes)
- ½ teaspoon salt
- ⅛ teaspoon black pepper
- ⅓ cup plain dry bread crumbs
- ¼ cup freshly grated Parmesan
- 2 Tablespoons salted butter
- Red pepper flakes to taste
- Fill a large pot ⅔ full with hot water. Add two teaspoons of salt to the water, cover the pot, and put the heat on high to let it come to a boil.
- While the water is heating, rinse the broccoli. Cut off and discard the thick stems, leaving the florets plus 2-3 inches of stems attached. Slice the florets in half the long way to thin out the stems a bit.
- Peel and chop ¼ a white onion and measure out ½ cup. Peel the garlic and chop it finely.
- When the water is boiling, add the broccoli to the pot and give it a stir. Lower the heat to medium high and let the broccoli cook uncovered for 4 minutes, or until just tender.
- While the broccoli is cooking, prepare the cheeses. Shred the Fontina in a food processor or blender, or use a box grater. Grate the Parmesan the same way.
- When the broccoli is just tender, drain it in a colander in the sink. Rinse the broccoli with cold water to stop the cooking.
- Preheat the oven to 375 degrees F. To make the cheese sauce, in a medium pot, melt 2 Tablespoons of butter over medium-high heat. Add the chopped onions and garlic and stir a bit. Let them cook for 3 minutes, or until the onions are tender. (If you are making a bigger batch of the base recipe, it might take longer for the onions to become tender.)
- Add the flour and whisk to combine. Cook the flour mixture for a minute.
- Add the milk to the pot, whisking constantly. Cook over medium-high heat, whisking constantly, for 5 minutes, or until it starts to thicken. (This will take longer if you are making a larger quantity of this recipe. Keep stirring until you have a thickened sauce.)
- Turn off the heat and stir in the Fontina until it is blended smoothly. Stir in the salt and pepper.
- In a small bowl, combine the Parmesan with the bread crumbs. (If you need to make bread crumbs, you can toast a slice of bread on medium high and then add it in pieces to your food processor or blender. Pulse the toast until it becomes crumbs.)
- To assemble the gratin, ladle some cheese sauce into the bottom of a 1-½ quart baking pan until the bottom is covered with sauce. Pat the broccoli dry with paper towels and add all of the broccoli to the baking pan in an even layer. Pour the rest of the cheese sauce all over the broccoli. Sprinkle on the bread crumb mixture evenly.
- Melt 2 tablespoons of butter in a microwavable bowl in the microwave or in a small pan on the stove. Drizzle the melted butter over the broccoli casserole.
- Bake the broccoli gratin for 20-25 minutes, uncovered, until it's lightly browned. Serve with red pepper flakes at the table.
- Store leftovers in the refrigerator for up to four days.
(Recipe Source: Inspired by a recipe for Broccoli with Mornay Sauce from Great American Recipes, 1988. Originally published on November 9, 2015 and updated now with additional information and photos.)