Easy Broccoli Cauliflower Casserole (Keto & Low Carb)

This easy Broccoli and Cauliflower Casserole is a low-carb take on your favorite comfort food that the whole family will enjoy. It requires less than 15 minutes of prep before baking in the oven!

Cooked broccoli cauliflower casserole in a white baking dish on a white countertop. A serving spoon is scooping some of the casserole.

Cheesy casseroles are perfect during the fall and winter seasons. This recipe takes a classic broccoli casserole, adds cauliflower and lightens it up by making it lower carb and just as delicious!

The cheesy goodness creates a great recipe that is the perfect addition to your holiday meal.

This is a popular Thanksgiving side dish to serve along with Garlic Mashed Potatoes, Turkey and Apple Cranberry Sauce.

Why You’ll Love This Recipe

  • It’s creamy, cheesy and delicious!
  • It’s naturally gluten free and low carb.
  • It’s the perfect side dish for Thanksgiving dinner or weeknight dinner.
  • It requires less than 15 minutes or prep work.
  • You can easily prep it in advance and reheat prior to serving.

Ingredients You Need

You will need the following simple ingredients to make this casserole with homemade cheese sauce.

ingredients for broccoli and cauliflower casserole bake
  • Broccoli and Cauliflower: You can use all broccoli or all cauliflower instead of a mix, if desired. They should be chopped into small florets.
  • Unsalted Butter: You can use ghee instead.
  • Onion and Garlic: These add flavor so don’t omit.
  • Cream Cheese: This helps create the cheesy creamy texture. You can substitute for mascarpone or even cottage cheese, but the texture and flavor of the casserole will be different.
  • Heavy Cream: You can use whole milk instead, if needed.
  • Dijon Mustard: Adds flavor.
  • Cheese: You will need a combo of mozzarella cheese and sharp cheddar cheese (white) for the best flavor. You can substitute for another type of cheese like gouda, fontina or gruyere.
  • Kosher Salt and Freshly Ground Black Pepper

How to Make Broccoli Cauliflower Casserole

This easy side dish is made completely from scratch and comes together with only 15 minutes of prep work.

mixing together ingredients for the casserole in a pan
  1. Blanch Veggies – Bring a large pot of water to a rolling boil. Add the cauliflower florets and broccoli florets and blanch for 1 minute. Drain well.
  2. Make the Creamy Cheese Sauce – Melt the butter in a large skillet over medium heat. Saute the onion for 3 to 4 minutes, then add the garlic. Stir in the cream cheese until melted, then stir in the heavy cream, mustard, salt, pepper, half of the cheddar and the mozzarella. Once the cheese is melted, stir in the broccoli and cauliflower.
  3. Assemble the Casserole – Preheat the oven to 400° F and butter an 8×8 casserole dish. Pour the broccoli and cauliflower mixture into the prepared baking dish and top with the remaining cheddar.
  4. Bake – Bake uncovered for 20 to 25 minutes, until cheese is bubbling and golden.

Garnish the casserole with freshly chopped parsley or sliced green onions before serving to add color, if desired.

broccoli cauliflower casserole ingredients in a casserole dish before going into the oven

Recipe Tips

  • Prep ingredients ahead of time: Save time by chopping the fresh vegetables in advance. You can save more time by blanching the broccoli and cauliflower ahead of time.
  • Drain the broccoli and cauliflower well: This prevents the sauce from becoming watery from the water stuck in between the veggies.
  • Add rotisserie chicken: Make a broccoli cauliflower chicken casserole by adding shredded cooked rotisserie chicken to the mixture before baking.
  • Add breadcrumbs: You can add bread crumbs or sprinkle crushed ritz crackers to the top of the casserole just prior to baking if you like casserole with breadcrumbs.

Storage

You can store leftover casserole in an airtight container in the fridge for up to 3 days. Reheat the leftovers in the microwave uncovered. Or you can reheat in the oven at 350° F for 20 to 25 minutes.

FAQs

Is it better to use fresh or frozen broccoli in a casserole?

Fresh is always best. You can use frozen broccoli or cauliflower in a casserole, but you will want to blanch it in water before adding it to the casserole. For frozen casserole, you will need to blanch it for 2 to 3 minutes.

Can you freeze broccoli cauliflower casserole?

We recommend dividing the uncooked casserole into freezer safe containers, making sure it is wrapped well or has an airtight cover. Store for up to 3 months. Remove from the freezer and bake the casserole at 400° F for 30 to 35 minutes or until it’s cooked through. It may take a little longer since it’s frozen.

Can you make broccoli and cauliflower casserole ahead of time?

Yes, you can bake it in advance and reheat just prior to serving. To reheat, cover with aluminum foil and heat in the oven at 350 degrees F. Reheat for 20 to 25 minutes or until reheated through.

Do you bake this casserole covered or uncovered

For best results, bake this casserole uncovered.

What to Serve with Broccoli Cauliflower Casserole

Broccoli and Cauliflower Casserole tastes great with a variety of meals. Try serving it with a few of our favorites!

A serving spoon with the broccoli cauliflower casserole is ready to serve the casserole on a plate.

Other Easy Casserole Recipes

You can never have too many easy casserole recipes. They help make dinner time easy and are the perfect side dish for a holiday table.

Did you try this cheesy Broccoli Cauliflower Casserole recipe? Leave a recipe rating and review below.

Cooked broccoli cauliflower casserole in a white baking dish on a white countertop. A serving spoon is scooping some of the casserole.

Broccoli Cauliflower Casserole

Yield: 5
Prep Time: 10 minutes
Cook Time: 30 minutes
Total Time: 40 minutes
This cheesy casserole is a low-carb twist on your favorite comfort food that the whole family will enjoy.
5 from 10 votes

Ingredients 

  • 3 cups broccoli florets
  • 2 cups cauliflower florets
  • 1 tablespoon unsalted butter or ghee
  • 1 medium onion, diced
  • 2 cloves garlic, minced
  • 6 ounces cream cheese, cubed, at room temperature
  • 1/3 cup heavy cream
  • 1 teaspoon dijon mustard
  • 1/2 teaspoon salt
  • 1/2 teaspoon ground black pepper
  • 8 ounces shredded white cheddar cheese,, divided
  • 3 ounces mozzarella cheese

Instructions

  • Preheat oven to 400 degrees F. Butter an 8×8 casserole dish and set aside.
  • Bring a large pot of water to a rolling boil; add the broccoli and cauliflower and blanch for 1 minute, then drain well.
  • Melt butter in a deep skillet over medium heat. Saute onion 3-4 minutes, then add the garlic.
  • Stir in the cream cheese until melted, and then stir in the heavy cream, mustard, salt, pepper, half of the cheddar, and the mozzarella. Once the cheese is melted, stir in the broccoli & cauliflower.
  • Pour the contents into the prepared dish and top with the remaining cheddar. Bake uncovered 20-25 minutes, until cheese is bubbling and golden.

Notes

SUBSTITUTIONS
  • You can use all broccoli or all cauliflower instead of a mix.
  • Cream Cheese: This helps give this dish the creamy cheesy texture. You can substitute for mascarpone or even cottage cheese, but the texture and flavor of the casserole will be different.
  • Heavy Cream: Use whole milk instead, if needed.
STORAGE:
  • Store in the refrigerator covered for up to 3 days. 
  • To freeze, store the uncooked casserole in a freezer safe container, making sure it is wrapped well or has an airtight cover. Store for up to 3 months. Then bake the casserole at 400 degrees for 30 to 35 minutes, or until cooked through. 
  • To reheat, cover with foil and heat in the oven at 350 degrees F. Reheat for 20 to 25 minutes or until heated through. 

Nutrition

Calories: 355kcal, Carbohydrates: 9.4g, Protein: 15.3g, Fat: 29g, Saturated Fat: 17g, Cholesterol: 95mg, Sodium: 570mg, Potassium: 405mg, Fiber: 3g, Sugar: 4g
Course: Main Course, Side Dish
Cuisine: American
Author: Ashley C.
If you try this recipe, don’t forget to leave a review below or share a photo and tag @spoonfulofflavor on Instagram.

This recipe was originally published in November 2018 and was updated in October 2020 with new process photos, tips and more.

6 comments on “Easy Broccoli Cauliflower Casserole (Keto & Low Carb)”

  1. I loved this casserole. So flavorful. It went right into my repeat file folder. Made it as a side dish with main course of Cod au Gratin, except I used tilapia instead. I increased it to 8 servings so adjusted the increments. I deleted the cream cheese as I felt the recipe had enough cheese without it. I also sliced the onion rather than chopping it, as I like the feel and texture of sliced onions. I also used up some of the cheese I had in my refrigerator rather than going out and buying more. However I did buy some fresh mozzarella cheese and attempted to shred/grate it. You didn’t say how to prepare it.
    I don’t like using pre-shredded cheese as a rule as it doesn’t melt as well as fresh does nor does it taste as good. I prefer the fresh cheeses so that’s what I did. In any event, it didn’t go well. BTW if anyone wants to shred or grate mozzarella cheese, freeze it and then grate/shred it. Otherwise it’s a complete mess. Regardless, even if you can shred/grate mozzarella cheese the right way, I wouldn’t use it again in this recipe. I thought it was way too stringy when mixing it up with everything, making it very difficult to spread it out evenly among all the other vegetables and ingredients, so next time I will use another cheese in it’s place. Great recipe. Thanks for sharing. It’s a keeper.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating




This site uses Akismet to reduce spam. Learn how your comment data is processed.