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A delicious spoon of broccoli casserole being picked up after baking
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5 from 4 votes

Broccoli Cheese Casserole

Cheesy, creamy, tangy, and jam packed with tender broccoli, this Broccoli Cheese Casserole is the side dish of your dreams! This recipe is loaded with onion, garlic, two different kinds of cheeses, then topped with buttery crackers! It doesn’t get any better than this!
Prep Time15 minutes
Cook Time35 minutes
Total Time50 minutes
Course: Main Course, Side Dish
Cuisine: American
Servings: 10 servings
Calories: 282kcal


  • 6 tbsp unsalted butter
  • 1 small sweet onion diced
  • 4 garlic cloves finely chopped
  • 4 tbsp all purpose flour
  • 2 cups whole milk
  • 1 cup sharp cheddar cheese shredded
  • 1 cup swiss cheese shredded
  • 1 tsp ground mustard
  • 1/4 cup sour cream
  • 3 1/2 cups frozen broccoli florets up to 4 cups
  • grated parmesan cheese
  • 1 1/2 cups crushed ritz crackers
  • kosher salt
  • fresh black pepper


  • Preheat the oven to 400 degrees and grease a shallow baking dish.*
  • Melt the butter in a large saucepan over medium heat. Add the diced onion, sprinkle in a pinch of salt, and stir to combine. Cook, stirring frequently, for 5 minutes. Reduce the heat to medium low if the onions start to brown too quickly.
  • Add garlic and cook, stirring frequently for 1 minute.
  • Add flour and cook, continuing to stir for 1 more minute.
  • Slowly pour in the milk, whisking constantly. Once all the milk has been added, cook for 3 minutes or until the milk just begins to simmer.
  • Add half of the shredded cheese, ground mustard, and sour cream, then reduce the heat to low and stir until the sauce begins to thicken. Season with salt and pepper to taste. Remove from heat.
  • Stir in the frozen broccoli. Transfer the broccoli and cheese mixture to the greased baking dish. Cover the casserole with the remaining cheese.
  • Bake the casserole for 15 minutes. Top with crushed ritz crackers and a heavy sprinkle of grated parmesan, then bake for an additional 5-8 minutes, or until heated through and bubbly.
  • Let cool for 5 minutes and enjoy!


Once fully baked, cheesy broccoli casserole will keep for 3-4 days. I like to portion out the casserole into small airtight containers, then tuck them away in the fridge or freezer for later.
This casserole can be reheated in the oven at 350 degrees for 15-20 minutes or in a microwave on high in 1-2 minute increments.
Totally! All you gotta do is prepare the casserole as directed, then top it with foil and refrigerate for up to 24 hours. When ready to eat, bake as instructed. You might need to add about 10 minutes of baking to account for the refrigeration. Do not top the casserole with crackers before storing, they’ll get soggy.
If you’d like to prep your casserole further ahead of time, cover it with two layers of heavy duty foil and freeze (unbaked) for up to 3 months. Thaw the casserole in the refrigerator for 24 hours, then bake fully according to instructions.


Calories: 282kcal | Carbohydrates: 15g | Protein: 11g | Fat: 20g | Saturated Fat: 12g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 5g | Trans Fat: 1g | Cholesterol: 52mg | Sodium: 284mg | Potassium: 237mg | Fiber: 1g | Sugar: 5g | Vitamin A: 770IU | Vitamin C: 30mg | Calcium: 320mg | Iron: 1mg