Go Back
A golden-brown Cauliflower and Broccoli Casserole topped with crispy bacon and fresh parsley, with a portion removed from the baking dish.
Reda

Creamy Cauliflower and Broccoli Casserole

A rich and cheesy baked casserole featuring tender cauliflower and broccoli florets in a creamy garlic and herb sauce, topped with a golden, crunchy breadcrumb topping. The ultimate comfort food side dish!
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings: 6 servings
Course: Main Course, Side Dish
Cuisine: American, Comfort Food
Calories: 385
Ingredients Equipment Method Notes

Ingredients
  

For the Vegetables
  • 1 medium head Cauliflower about 1.5 lbs, cut into bite-sized florets
  • 1 large head Broccoli about 1 lb, cut into bite-sized florets
For the Creamy Cheese Sauce
  • 4 tbsp Unsalted Butter
  • 1/4 cup All-Purpose Flour
  • 2 cups Whole Milk warmed
  • 1 tsp Dijon Mustard
  • 1 tsp Garlic Powder
  • 1/2 tsp Onion Powder
  • 1/2 tsp Smoked Paprika
  • 1/4 tsp Ground Nutmeg
  • 1/2 tsp Salt or to taste
  • 1/4 tsp Black Pepper freshly ground
  • 8 oz Sharp Cheddar Cheese shredded (about 2 cups)
  • 4 oz Gruyère Cheese shredded (about 1 cup)
For the Topping
  • 3/4 cup Panko Breadcrumbs
  • 2 tbsp Unsalted Butter melted
  • 2 tbsp Grated Parmesan Cheese

Equipment

  • 9x13 Inch Casserole Dish
  • Large Pot
  • Saucepan
  • Whisk
  • Mixing Bowl

Method
 

Prepare the Vegetables and Oven
  1. Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch casserole dish.
  2. Bring a large pot of salted water to a boil. Add the cauliflower and broccoli florets and blanch for 3-4 minutes, until just crisp-tender. Drain the vegetables very well and pat them dry with a paper towel to remove excess moisture. This is key to preventing a watery casserole. Set aside.
Make the Creamy Cheese Sauce
  1. In a medium saucepan over medium heat, melt 4 tablespoons of butter. Whisk in the all-purpose flour and cook for 1 minute, stirring constantly, to create a roux.
  2. Gradually pour in the warm milk while whisking continuously to prevent lumps. Continue to cook, whisking frequently, for about 5-7 minutes, until the sauce thickens enough to coat the back of a spoon.
  3. Remove the saucepan from the heat. Stir in the Dijon mustard, garlic powder, onion powder, smoked paprika, nutmeg, salt, and pepper. Add the shredded cheddar and Gruyère cheeses in handfuls, stirring until each batch is fully melted and the sauce is smooth before adding the next.
Assemble and Bake
  1. Gently fold the blanched cauliflower and broccoli florets into the cheese sauce until they are evenly coated. Pour the mixture into the prepared casserole dish and spread it into an even layer.
  2. In a small bowl, combine the panko breadcrumbs, 2 tablespoons of melted butter, and the grated Parmesan cheese. Toss until the breadcrumbs are evenly moistened.
  3. Sprinkle the breadcrumb topping evenly over the casserole.
  4. Bake uncovered for 20-25 minutes, or until the sauce is bubbly and the topping is golden brown and crispy.
  5. Let the casserole rest for at least 10 minutes before serving. This allows the sauce to set up.

Notes

Tips for Success:
  • Avoid a Watery Casserole: The most important step is to dry the blanched vegetables thoroughly before adding them to the sauce. Excess water will thin out the cheese sauce.
  • Cheese Variations: Feel free to experiment with other good melting cheeses like Monterey Jack, Fontina, or a classic sharp white cheddar.
  • Make-Ahead: You can assemble the casserole (without the topping) up to 24 hours in advance. Cover and refrigerate. When ready to bake, add the topping and increase the baking time by 10-15 minutes.
  • Storage: Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in the oven or microwave.