Healthy Make-ahead Broccoli and Cauliflower Casserole with Creamy Cheddar Leek Sauce and Crunchy Panko Breadcrumb topping on

broccoli and cauliflower casserole

  • Author: Katie Webster
  • Prep Time: 30 minutes
  • Cook Time: 30 minutes
  • Total Time: 1 hour 15 minutes
  • Yield: 10 cups 1x
  • Category: Side Dish
  • Method: Baked
  • Cuisine: American


This make-ahead broccoli and cauliflower casserole is a healthy and delicious option for a covered dish for the holidays. The cauliflower and broccoli are coated in a creamy leek cheddar sauce and topped with crunchy panko breadcrumb topping.



  • 1 medium head of cauliflower
  • 2 large broccoli crowns (1 pound)
  • 2 tablespoons plus 1 teaspoon extra-virgin olive oil, divided
  • 1 large leek, white and pale green part only, sliced and washed
  • ¾ teaspoon salt
  • 1/3 cup all-purpose flour
  • 2 cups fat-free milk (lactose-free if desired)
  • 6 ounces sharp lactose free cheddar, shredded (I used Cabot Alpine)
  • ¼ teaspoon ground white pepper
  • ¼ cup panko, preferably whole-wheat
  • 1 teaspoon paprika
  • ¼ teaspoon garlic powder


  1. Bring a large pot of salted water to a boil. Set a large bowl of ice water to the side.
  2. Core cauliflower and cut into medium florets. Cut off broccoli stems and cut into florets. Blanch cauliflower 3 minutes in boiling water. Remove from the water with a slotted spoon or small strainer and transfer immediately to the ice bath to stop it from cooking. Repeat with the broccoli, cooking for 3 minutes, and shocking in the ice bath. Drain the vegetables very well. Reserve bowl for mixing in step 4.
  3. Prepare cheese sauce. Heat 2 tablespoons oil in a large saucepan over medium-high heat. Add leek and ¾ teaspoon salt and cook, stirring often until the leek is soft, 4 to 5 minutes. Sprinkle the flour over the leek and stir to coat. Add milk and bring to a simmer, over high heat, stirring constantly. Cook until bubbling and thickened, 1 to 2 minutes longer. Remove from heat and stir in cheese and pepper until the cheese is completely melted into the sauce.
  4. Preheat oven to 350 degrees F. Coat a 2 ½ quart baking dish with cooking spray. Stir panko, the remaining 1 teaspoon oil, paprika and garlic powder in a small dish until evenly moist. Mix the vegetables and cheese sauce together in the reserved bowl. Transfer to the prepared baking dish.
  5. Top with the panko mixture. Bake until the casserole is hot all the way through, the sauce is bubbling and the vegetables are tender, 28 to 35 minutes. Let cool 15 minutes before serving.


TO MAKE AHEAD: Prepare through step 4 (do not pre-heat oven in step 4.) Cover casserole in foil and refrigerate up to 24 hours in advance. Preheat oven, and bake casserole covered for 25 minutes. Remove foil and continue with topping with the breadcrumb mixture and baking as directed in step 5.


  • Serving Size: 1 cup
  • Calories: 171
  • Sugar: 3 g
  • Sodium: 377 mg
  • Fat: 10 g
  • Saturated Fat: 5 g
  • Carbohydrates: 12 g
  • Fiber: 2 g
  • Protein: 8 g

Get my FREE ebook, The Best Weeknight dinners!

It includes 15 of my family's favorites -- recipes and meals we go back to over and over again -- including simple to follow instructions and easy to find ingredients.

You have Successfully Subscribed!