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Cheddar Broccoli Cauliflower Gratin

Scrumptious cheddar broccoli cauliflower gratin with a crispy breadcrumb topping. This delicious cheesy side dish is perfect for serving guests during the holiday season, or pairing with your favorite protein for a yummy weeknight dinner!

Prep Time
15 mins
Cook Time
1 hour
Total Time
1 hour 15 mins

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Every Christmas eve, my husband’s good family friend, Lori, throws a huge celebration filled with food, cocktails and good company. She makes incredible savory chicken and dumplings, an outrageously good apple walnut spinach salad and just last year she introduced a new-to-me cheesy veggie gratin filled with cauliflower, carrots and broccoli.

I knew I really liked it after one bite of cheddar cheesy goodness, but after scooping seconds and then thirds onto my plate, I realized that a true love affair was going down between me and this fabulous gratin.

A couple of years ago I decided to bring my version of Lori’s cheddar broccoli cauliflower gratin to you, and of course, in consideration for your Thanksgiving menu (aka my favorite day).

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broccoli cauliflower gratin in a baking dish with a spoon

What is a “gratin?”

Gratin refers to a recipe that’s topped with butter, cheese and/or breadcrumbs and then baked so that a nice crust forms. In my dad’s cheesy au gratin potatoes the potatoes are covered in a delicious cheese sauce and baked to bubbly perfection. In this cauliflower broccoli gratin we’re adding both cheese sauce and breadcrumbs to get a lovely toasty texture on top.

broccoli, cauliflower and carrots in a baking dish

Ingredients in this cheddar broccoli cauliflower gratin

This isn’t your average butter-filled veggie gratin. Instead, it’s made with a lightened-up sharp cheddar cheese sauce that only uses a few tablespoons of butter, yet is still rich, flavorful and generously coats all of the veggies with plenty of cheesy love. You’ll only need a few simple, inexpensive ingredients to make the recipe (and they’re all from ALDI!)

  • Cauliflower, broccoli & carrots: this is what was in Lori’s gratin, and now it’s in mine too! You’ll want to make sure your florets aren’t too large, otherwise they won’t all fit nicely in your pan.
  • Butter: I prefer salted butter in both cooking and baking, simply because it adds just a little more flavor.
  • Flour: you can use regular flour, but know that whole wheat or a 1:1 gluten-free all purpose flour are also options.
  • Milk: I love using unsweetened almond milk in all of my baking and cooking, but you can also use regular milk if that’s your preference.
  • Garlic powder: essential for adding additional flavor to the cheese sauce!
  • Cheese: I always recommend shredding your own cheese from a block of cheese, as it tends to melt better! We’re using cheddar for extra delicious flavor.
  • Parmesan: in addition to cheddar, we’re using parmesan cheese for nice, cheesy flavor
  • Panko breadcrumbs: while topping this gratin is optional, I do recommend it! Everyone loves a good crunchy breadcrumb coating.

pouring cheddar cheese sauce over veggies for a broccoli cauliflower gratin

Can I make it vegan?

Sure! Feel free to use vegan butter and your favorite vegan cheeses in this recipe to make a dairy free and vegan cauliflower broccoli gratin. Be sure to use a dairy free milk as well.

unbaked broccoli cheddar cauliflower gratin in a baking dish

Easy ways to customize

This cheddar broccoli cauliflower gratin is easy to make and even easier to customize! Here are some great ways to make it your own:

  • Choose your cheese. I love the flavor that cheddar gives this dish but feel free to use your favorite cheese! Gruyere, a smoky gouda, or even a spicy cheese would be delicious.
  • Go extra savory. If you’re not serving vegetarians I think adding cooked bacon or ham to the cheese sauce would be SO delicious.
  • Pick the veggie ratio. Feel free to use any combo of veggies you’d like! All cauliflower or all broccoli would work just as well.

cheesy cauliflower broccoli gratin in a baking dish

Cheesy cauliflower broccoli gratin in 5 simple steps

  1. Prep your pan. Start by greasing a 2 1/2 quart baking dish and adding all of your veggies.
  2. Make the cheese sauce. Melt butter in a skillet over medium heat and make a roux by alternating flour and milk. Bring the mixture to a boil, then reduce it to low and stir it every so often until a gravy-like texture forms. Stir in the garlic powder, salt & pepper, then fold in the cheeses.
  3. Assemble the gratin. Pour your cheese sauce all over those veggies, cover with foil and bake.
  4. Prep your breadcrumbs. While the gratin is baking, mix breadcrumbs with melted butter.
  5. Top, bake & serve. Remove the gratin from the oven, top with breadcrumbs, and then bake it again until veggies are fork tender. Serve & enjoy!

scooping cheddar broccoli cauliflower gratin out of a skillet

Make it ahead of time

If you want to make this recipe ahead of time and save time on Thanksgiving Day, simply make the recipe as directed, except do NOT add breadcrumbs. Instead, cover and place in the fridge for up to a day or two. Once ready to enjoy, bake as directed in the instructions, adding the breadcrumbs after 30 minutes of baking, then baking again uncovered.

scooping broccoli cauliflower gratin out of a baking pan

Storing & reheating tips

  • To store: simply store this broccoli cauliflower gratin in the refrigerator in individual, airtight containers or cover the entire pan and place it in the refrigerator. It will stay good for up to 5 days.
  • To reheat: reheat individual portions in the microwave or place the pan back in the oven until heated through.

More delicious Thanksgiving recipes

Get all of our Thanksgiving recipes here, and our best tips for hosting here!

This recipe is perfect to serve during Thanksgiving, or just anytime you’re looking for a healthy, yet deliciously cheesy and easy side dish!

I hope you all love this cheddar broccoli cauliflower gratin! If you make it be sure to leave a comment and a rating so I know how you liked it. Enjoy, xo!

Cheddar Broccoli Cauliflower Gratin

4.75 from 8 votes
cheddar cauliflower broccoli gratin in a baking pan
Course Side Dish, Thanksgiving, Vegetarian
Cuisine American
Keyword broccoli cauliflower gratin, cauliflower gratin, thanksgiving side dish, vegetarian side dish
Prep Time 15 minutes
Cook Time 1 hour
Total Time 1 hour 15 minutes
Serves 8

Scrumptious cheddar broccoli cauliflower gratin with a crispy breadcrumb topping. This delicious cheesy side dish is perfect for serving guests during the holiday season, or pairing with your favorite protein for a yummy weeknight dinner!


  • Nonstick cooking spray or olive oil, for greasing the baking dish
  • For the veggies:
  • 4 cups medium broccoli florets (from 1 head broccoli)
  • 4 cups medium cauliflower florets (from 1 head cauliflower)
  • 3 medium carrots, sliced
  • For the cheese sauce:
  • 2 tablespoons salted butter
  • cup all purpose flour
  • 2 1/3 cups unsweetened almond milk (or milk of choice)
  • 1 teaspoon garlic powder
  • ¼ teaspoon salt, plus more to taste
  • Lots of freshly ground black pepper
  • 8 ounces sharp cheddar cheese, cut into small cubes
  • 1/3 cup parmesan cheese
  • For the topping:
  • 3/4 cup panko breadcrumbs
  • 1 tablespoon salted butter, melted


  1. Preheat your oven to 375 degrees F. Spray 2 ½ quart baking dish or 9x9 inch baking pan with nonstick cooking spray, or grease with olive oil or butter. Add broccoli florets, cauliflower florets and sliced carrots to prepared baking dish. Set aside.
  2. In a large skillet or pot add butter and place over medium heat. Once butter is melted, whisk in a little bit of the flour and then slowly add in milk, a little bit at a time, alternating with the flour and vigorously whisking away any lumps. Bring mixture to a boil, then reduce heat to low and simmer for a few minutes stirring every so often, until the sauce thickens up similar to a gravy. Stir in garlic powder, salt and LOTS of freshly ground black pepper. If the sauce is WAYYY too thick, feel free to add in a splash more milk. If the sauce is two thin, stir in another tablespoon of flour.
  3. Next add in sharp cheddar cheese and parmesan cheese and stir until completely melted into the sauce. Taste and add more salt and pepper, if desired. A fairly salty cheese sauce is best!
  4. Pour cheese sauce evenly over the veggies in the baking dish. Cover with foil and bake for 30 minutes.
  5. In a medium bowl, mix together breadcrumbs with 1 tablespoon of melted butter.
  6. After 30 minutes of baking time, remove the foil from the baking dish, evenly sprinkle breadcrumbs on top of the veggies and bake UNCOVERED for 20-30 minutes more until breadcrumbs are slightly golden brown and veggies are fork tender. Serve 6-8.

Recipe Notes

You can easily make this recipe gluten free by using a gluten free 1:1 flour and gluten-free breadcrumbs.

Make it ahead of time: simply make the recipe as directed, except do NOT add breadcrumbs. Instead, cover and place in the fridge for up to a day or two. Once ready to enjoy, bake as directed in the instructions, adding the breadcrumbs after 30 minutes of baking, then baking again uncovered.

Servings: 8 servings
Serving size: 1 serving (based on 8)
Calories: 248kcal
Fat: 15.7g
Saturated fat: 8.6g
Carbohydrates: 18.2g
Fiber: 3.9g
Sugar: 3.5g
Protein: 12.9g

Recipe by: Monique Volz // Ambitious Kitchen | Photography by: Eat Love Eats

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