Broccoli-Cauliflower Gratin with a grownup Brie and cheddar cheese sauce is a side dish everyone loves to see on the table at dinnertime.
Leftovers create an amazing creamy soup too!
Easy Vegetable Side Dish
Broccoli and Cauliflower Gratin is an easy recipe to customize to your own taste. Roast or steam the vegetables and select any favorite cheese with good melting properties from the list below.
You’ll also find simple substitutes for making it gluten-free with sweet rice flour while maintaining the integrity and quality of the dish.
How to Make a Great Cheese Sauce
- Know your cheese. The selection of cheese is important for melting properties and flavor. We choose Brie to deliver a creamy, luxurious texture with extra-sharp cheddar and Parmesan to bring some punch.
⇒ Gruyere, Gouda, Fontina, Asiago, Provolone, Swiss, Taleggio, or Reblochon-Style cheese are all terrific choices for an amazing cheese sauce. Mozzarella can be used but is challenging to keep smooth and not stringy. Use only pure, real cheese, and never cheese foods. - Balance with acid and a touch of spice. An acid like Dijon paired with a tiny bit of spice from cayenne brings a welcome contrast to heavier foods and sauces.
- Grate the cheese yourself. Pre-grated cheese will often have a coating of cellulose to keep it from sticking together in the package. This can inhibit a cohesive melting or leave the sauce slightly gritty. Grate the cheese from a block using a small hole grater—the more finely grated it is, the easier it will melt.
- Go low and slow. Keep the heat low enough so the sauce forms large bubbles that pop slowly, like scattered raindrops. Stir constantly to keep everything smooth and silky.
- Don’t overcook cheese sauce. The proteins in cheese will change the consistency if overheated. Bring the cheese to room temperature so it isn’t cold when adding it to the sauce. After the sauce has thickened, remove the sauce from heat before adding the cheese. The heat from the sauce will melt the cheese as you stir it in.
Just in case the phone rings or phone notifications distract (it happens), here’s an excellent resource for TIPS to save a broken sauce: Taste of Home, How to Save a Broken Sauce
Broccoli & Cauliflower Gratin Step by Step
- Roast vegetables at 400°F for 8-10 minutes.
- Make the cheese sauce by heating the butter in a saucepan until bubbly. Whisk in flour and cook on medium-low for 3-4 minutes. Reduce heat to low and whisk in milk, Dijon, and a pinch of cayenne; barely simmer on low about 5 minutes. Remove from heat and stir-in brie and cheddar cheese, continuing to stir until cheese is melted.
- Pour the sauce over the vegetables and sprinkle with Parmesan and bread crumbs. Spray crumbs lightly with cooking spray.
- Broil for 10 minutes until the cheese is bubbly and topping is lightly browned in spots.
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Gratin One Night, Soup for Lunch
My advice is to make more than you think you’ll need because it makes a fantastic cream soup for lunches. To make soup with leftovers, simply place leftovers in a food processor or use an immersion blender to puree until smooth.
Gently warm in a saucepan and thin with chicken broth or water to the desired consistency. Garnish with fresh chopped scallions or chives to serve.
More Vegetable Side Dish Recipes Your Family Will Love
- Tuscan Roasted Broccoli
- Roasted Vegetable Medley
- Vegetable Tian
- Grilled Asparagus with Cotija Cheese
- Skillet Roasted Cauliflower Mash
- Grilled Cabbage with Classic Caesar Dressing
- Roasted Brussels Sprouts with Garlic Aioli
- Roasted Asparagus with Caramelized Onions and Blue Cheese
Broccoli-Cauliflower Gratin
Broccoli and cauliflower cradled in a Brie and cheddar cheese sauce and topped with panko bread crumbs for a creamy-crunchy vegetable side dish.
Servings: 6 Servings
Ingredients
- 16 ounces cauliflower , cut into bite-sized pieces slightly smaller than the broccoli
- 16 ounces broccoli cut into bite-sized pieces
- Sea salt and freshly ground pepper
- 2 1/2 tablespoons butter
- 2 tablespoons white whole wheat flour or sweet rice flour for gluten-free
- 1 cup whole milk plus more to thin sauce as desired
- 1/2 teaspoon Dijon mustard or 1 teaspoon lemon juice
- Pinch cayenne pepper
- 1 cup Brie cheese cut into small cubes
- 3/4 cup grated extra-sharp cheddar cheese
- 1/2 cup grated Parmesan cheese
- 1/2 cup panko bread crumbs or gluten-free Panko crumbs
- pinch ground white pepper
- Olive oil cooking spray or duck fat spray
- 9×13 Broiler-safe baking dish
Instructions
- Season cauliflower and broccoli with salt and pepper. Roast in a 400°F oven for 8-10 minutes -OR- steam in a large skillet with a lid and 1/3 cup water over medium heat for 5-6 minutes until crisp-tender. (Add more water, if needed)
- While the vegetables are cooking, melt 2 1/2 tablespoons butter In a medium saucepan. Use this melted butter to brush in the baking dish and then transfer vegetables to the baking pan in a single layer. Heat the broiler and position rack 8-10 inches from the heating element. Note: If you don’t have a broiler-safe dish, bake on convection bake at 400°F – this will brown the top more efficiently without overcooking the cheese sauce.
- Return the remaining butter to the stove and heat until bubbly. Add 2 tablespoons flour and whisk over medium heat until bubbly. Continue to cook on medium-low for 3-4 minutes to incorporate the flour fully.
- Reduce heat to low and whisk in 1 cup of milk, 1/2 teaspoon Dijon, and a pinch of cayenne; continue to stir and gently simmer on low about 5 minutes or until sauce thickens. Remove from heat and stir-in 1 cup cubed Brie and 3/4 cup cheddar cheese, continuing to stir until cheese is melted. Taste and season with salt and pepper.
- Pour the sauce over the vegetables and sprinkle with Parmesan and bread crumbs. Spray crumbs lightly with cooking spray and broil for 10 minutes (depending on broiler – watch closely) until the cheese is bubbly and topping is lightly browned in spots.
Notes
Make Ahead TIP: Make ahead and cover for up to an hour. Dress with the bread crumbs and Parmesan just before putting in the oven.
Make it Gluten-Free: Substitute sweet rice flour for wheat flour and use gluten-free bread crumbs in place of the regular bread crumbs.
Cheese TIP: Brie has a soft white rind that is fine to add to the sauce, however, remove any dry edges as they do not melt as well. The soft rind may not completely melt, but that’s okay and not noticeable in the final dish.
Nutrition
Serving: 6g | Calories: 291kcal | Carbohydrates: 12g | Protein: 16g | Fat: 20g | Saturated Fat: 12g | Cholesterol: 61mg | Sodium: 508mg | Potassium: 402mg | Fiber: 3g | Sugar: 3g | Vitamin A: 2045IU | Vitamin C: 38.8mg | Calcium: 373mg | Iron: 2mg
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If you try this or any other recipe on the blog, please rate the recipe and let me know how it went for you in the comments below. It makes my day to hear from you!
Rose Robinson says
You use the phrase “We choose Brie to deliver a creamy, decadent texture”, but DECADENT means decaying, literally. For example, a decadent society can be one of affluence but with immoral behaviour.
Have you thought of using “a creamy, luxurious texture” instead?
Or even “a rich, creamy texture”?
So saying…
You’re recipe is delicious, well written with great cooking tips.
Thank you
Judy Purcell says
Hi Rose, thank you for the writing suggestion. I agree with you that is a better way to describe it. 🙂 Glad you enjoyed the recipe too!
Faith says
Why? Just why?
K says
This was easy and delicious. The only thing I added was 2 large shallots and some garlic powder. I made this for thanksgiving to have 10 servings. I think my husband will try to eat half by himself. Thank you for this recipe.
Judy Purcell says
Hi K, adding shallots sounds great! I’m so glad you enjoyed it — thank you for taking the time to let me know. 🙂
STACEY CRAWFORD says
Oh my, this is so tasty and comforting! I love that there is a gluten-free option and that I can make soup with the leftovers.
chihyu says
OMG! Everything looks so good. I’m drooling just by looking at it!
Anne Lawton says
This is the perfect side dish to make ahead! I love all of the ingredients in this!
paleoglutenfreeguy says
You make veggies look straight-up indulgent!
jennifer says
Literally my mouth is watering for this and it’s only 7am — I love the cruciferous veggie blend in there, winning!
Tessa Simpson says
The brie gives a special flavor to this amazing veggie casserole…I could eat it every day!!
Linda says
Yum! This gratin looks so creamy comforting, and it’s a perfect dish for a busy weeknight dinner.
Joni Gomes says
What a savory and cheesy side dish!! I love broccoli and cauliflower already and with cheese like this…oh mama!
Karen (Back Road Journal) says
Your cheese sauce makes your gratin very special…I can’t wait to give this dish a try.
Judy Purcell says
Oh Karen, I hope you do! You’ll love it.
Jean McCormick says
I’ve been eyeing this recipe for a few weeks, and would like to serve it at Christmas for dinner, but my brother can’t eat cheese, poor thing, and my family is very cholesterol-conscious. Do you have an idea for another sauce for this, maybe a bechamel sauce? I think one egg yolk would be better than all this cheese, and I could make it go farther. What do you suggest?
Judy Purcell says
Hi Jean,
If you are wanting to avoid adding cheese to the sauce, you can omit the cheese all together, which leaves you with a basic bechamel sauce. To add a little flavor, you could saute shallot, garlic, or even some mushrooms in the butter before finishing the sauce to give it umph and depth of flavor. So sorry for your brother not being able to eat cheese — what a bummer for him! Hope this helps. 🙂
Have a Merry Christmas dinner!
Jed Gray (sportsglutton) says
Nothing to hate about this recipe, especially given that you can make the leftovers into a palate pleasing soup. Good stuff and congrats on your Broncos winning their opener!!
Nancy/SpicieFoodie says
You’ve certainly been busy. I love love your gratin recipe, my husband would too. Thanks for sharing and for getting the taste buds going:)
Judy Purcell says
Thanks, Nancy for stopping by and saying hello. I think you’d like the gratin quite a lot. 🙂
kitchenriffs says
Wow, what a versatile dish! I love gratins, and I’d probably serve the leftover reheated. But the option of making it into a soup is terrific! Good stuff – thanks.
Judy Purcell says
The leftovers do reheat quite well by themselves, but this time I couldn’t resist the idea of a simple soup.
Raymund says
That soup looks good!
Maureen | Orgasmic Chef says
What a great post and that gratin looks delicious!
Judy Purcell says
Thanks, Maureen. 🙂
Rebecca says
How do I turn this into soup?
Judy Purcell says
Hi Rebecca!
Place leftovers in a food processor and puree until smooth then gently warm in a sauce pan with a little garlic and onion powder, as well as enough chicken broth to thin soup for desired consistency (this will depend on how much you have leftover). Garnish with a tomato slice and chopped scallions or chives to serve. And of course, you can call me if this doesn’t make sense or you need any further guidance. 🙂
Rebecca says
THANK YOU!!! 😀
ChgoJohn says
If there’s a gratin in the oven, if must be Fall — or pretty darn close. This looks delicious, Judy, but I must admit, I’d probably be thinking about that soup the entire time I was enjoying the gratin. It just sounds soo good!
Judy Purcell says
I’m the same way, John. I still haven’t decided if I make Thanksgiving turkey for the turkey or the sandwiches. 😉
Barbara Bamber | justasmidgen says
I love the sounds of what you’re cooking up in your kitchen! Fantastic gratin and a wonderful start to fall!! xx
Judy Purcell says
As much as I loooooove summer grilling, fall holds my favorite flavors. 😀
Top cuisine avec Lavi says
Looks amazing! Great recipes!
Judy Purcell says
Thank you so much for sayin’ so! 🙂