Broccoli Cheddar Cornflake Casserole

Featured in: Hearty Comfort Dinners

This comforting casserole blends tender broccoli florets, sharp cheddar cheese, and a creamy mushroom mixture for a rich and satisfying dish. Fresh onion and garlic create depth, while a crunchy cornflake topping gives every bite a buttery finish. Quick to prepare and baked until golden, it's an easy vegetarian option perfect for both side dishes and hearty mains. Make it richer with a touch of Parmesan, or customize the filling and topping to suit dietary needs and personal preferences. Serve warm and enjoy the balance of creaminess and crunch.

Updated on Fri, 17 Oct 2025 10:07:55 GMT
Golden Broccoli & Cheddar Casserole with crispy cornflake topping bubbling hot from the oven. Save
Golden Broccoli & Cheddar Casserole with crispy cornflake topping bubbling hot from the oven. | smokyfeast.com

This broccoli and cheddar casserole delivers the comfort of classic American home cooking with a cheesy creamy base and a crisp buttery cornflake topping. It is the kind of recipe I turn to when I need a crowd pleasing side that feels special yet simple enough to whip up for a weeknight dinner or holiday table.

I started making this when my kids declared they hated broccoli but when I appeared at the table with bubbling cheese and a golden crunch on top the whole dish disappeared. Now it is a regular request for both potlucks and lazy Sunday dinners.

Ingredients

  • Fresh broccoli florets: The star of the dish Choose heads that are firm bright green and show no yellowing
  • Yellow onion: Adds aromatic sweetness Use one that feels heavy for its size and has smooth skin
  • Garlic: Gives depth and a savory base Go for plump, unblemished cloves
  • Sharp cheddar cheese: Packs bold flavor and melts smoothly Buy a block and shred it yourself for best texture
  • Sour cream: Brings tang and creaminess Full fat delivers the richest taste
  • Whole milk: Gives moisture and a silkier sauce Use fresh milk for best results
  • Unsalted butter: Works in both the base and topping Look for pale yellow sticks with clean dairy aroma
  • Condensed cream of mushroom soup: Binds the mixture with a velvety finish Opt for low sodium if you like
  • Dijon mustard: Adds a little zip and subtle heat Reach for a jar with real mustard seeds
  • Salt: Enhances all the other flavors Use kosher or sea salt for best control
  • Freshly ground black pepper: Balances the richness Whole peppercorns give the most flavor when ground fresh
  • Cornflakes: Turn crisp and golden on top Choose a plain variety that stays crunchy in milk and check for freshness by the best by date

Instructions

Prepare the Oven and Pan:
Preheat your oven to 350 degrees Fahrenheit or 175 degrees Celsius and grease a 9 by 13 inch baking dish generously so nothing sticks later
Blanch the Broccoli:
Bring salted water to a rolling boil in a large pot Drop in all the broccoli florets and let them cook for two to three minutes just until they turn bright green and slightly tender Drain quickly and set aside to keep the color and texture
Sauté the Aromatics:
In a large skillet melt two tablespoons of butter over medium heat Add the finely chopped onion and cook for about three minutes stirring until translucent and soft Add in the garlic and let it sizzle for just one minute to release its aroma without browning
Combine Everything:
Transfer the sautéed onion and garlic into a large mixing bowl Add the blanched broccoli shredded cheddar cheese sour cream milk condensed soup Dijon mustard salt and pepper Stir until every bit of broccoli is coated with cheesy sauce
Fill the Baking Dish:
Spread the cheesy broccoli mixture evenly in your prepared baking dish pressing it gently so the top is fairly level
Make the Cornflake Topping:
In a small bowl combine the crushed cornflakes and the melted butter Toss until every flake is coated in butter for maximum crackle then sprinkle the mixture evenly over the casserole
Bake Until Golden and Bubbly:
Slide the dish onto the oven’s center rack and bake for thirty to thirty five minutes until you see the edges bubbling and the cornflakes on top are golden brown
Let It Rest:
Take the casserole out and let it cool for five minutes so the cheese sets up just enough to serve tidy squares
Creamy Broccoli & Cheddar Casserole: Imagine tender broccoli in rich cheese sauce, comforting American fare. Save
Creamy Broccoli & Cheddar Casserole: Imagine tender broccoli in rich cheese sauce, comforting American fare. | smokyfeast.com

My favorite part is the sharp cheddar I always buy an extra aged variety because the boldness comes through every creamy bite. One Thanksgiving my dad asked for seconds and thirds after swearing he didn’t like broccoli so now it’s officially on our family’s holiday menu.

Storage Tips

Leftovers keep well covered in the fridge for up to three days. To reheat cover with foil and warm in a 350 degree oven for fifteen minutes or until hot throughout. The topping will crisp up again nicely.

Ingredient Substitutions

You can use frozen broccoli just thaw and blot dry before stirring in. For a mushroom free option try a cream of celery soup or your favorite homemade béchamel sauce. Swap cheddar out for Monterey jack or half Gruyère for extra richness.

Serving Suggestions

I love this alongside maple glazed carrots and roasted potatoes at a family dinner. Make it a main by stirring in some cooked brown rice or topping with sliced hard boiled eggs for extra protein. This also works beautifully as a brunch bake.

Cultural Notes

Broccoli casseroles like this started on American tables in the mid twentieth century when convenience foods and hearty comfort cooking really took off. The cornflake topping became a favorite finish for home cooks looking to add crunch without extra fuss.

Seasonal Adaptations

Add steamed cauliflower or green beans for variety Try using smoked cheddar for a winter twist A sprinkle of fresh chives over the baked casserole gives it spring garden flavor

Success Stories

This recipe has become a white elephant potluck legend in my neighborhood. Even picky eaters usually come back for seconds. One friend texted me the night after the party for the recipe after her seven year old finally decided green stuff was delicious.

Freezer Meal Conversion

Assemble the casserole up to the baking step then wrap tightly and freeze for up to two months. Thaw overnight in the fridge then bake as directed adding five to ten extra minutes until bubbling and hot.

Homemade Broccoli & Cheddar Casserole, a cheesy, vegetarian family favorite, baked until perfectly golden. Save
Homemade Broccoli & Cheddar Casserole, a cheesy, vegetarian family favorite, baked until perfectly golden. | smokyfeast.com

Serve piping hot for best flavor and texture. This casserole is sure to win over even the most skeptical veggie eaters.

Kitchen Questions

Can frozen broccoli be used?

Yes, thaw frozen broccoli and drain well before mixing to avoid excess moisture breaking down the casserole texture.

How do I make it gluten-free?

Choose gluten-free cornflakes and soup, or prepare a homemade cream sauce with cornstarch and broth.

What cheese works best for this dish?

Sharp cheddar is recommended for flavor and meltability, but try blending with Parmesan or Gruyère for added depth.

Can this casserole be made ahead?

Yes, assemble fully without the topping, refrigerate for up to a day, then add cornflakes and bake just before serving.

Can I add protein for a heartier dish?

Stir in cooked rice, quinoa, or shredded chicken for extra substance if desired.

What sides pair well?

Serve with a light salad, roasted vegetables, or fresh bread to complement the cheese and broccoli flavors.

Broccoli Cheddar Cornflake Casserole

Cheesy broccoli casserole paired with crunchy cornflakes. A family-friendly, comforting vegetarian side or main.

Prep duration
15 min
Heat time
35 min
Complete duration
50 min
Created by Jackson Reed


Skill Level Easy

Heritage American

Output 6 Portions

Nutrition Labels Meat-Free

What You'll Need

Vegetables

01 6 cups fresh broccoli florets (approximately 2 large heads)
02 1 small yellow onion, finely chopped
03 2 cloves garlic, minced

Dairy

01 2 cups sharp cheddar cheese, shredded
02 1 cup sour cream
03 1/2 cup whole milk
04 2 tablespoons unsalted butter
05 2 tablespoons unsalted butter, for topping

Pantry

01 1 can (10.5 ounces) condensed cream of mushroom soup
02 1 teaspoon Dijon mustard
03 1/2 teaspoon salt
04 1/4 teaspoon freshly ground black pepper

Topping

01 2 cups cornflakes, lightly crushed
02 2 tablespoons unsalted butter, melted

Method

Phase 01

Prepare Oven and Baking Dish: Preheat oven to 350°F. Coat a 9x13-inch baking dish with nonstick spray or lightly grease with butter.

Phase 02

Blanch Broccoli: Bring a large pot of salted water to a boil. Add broccoli florets and blanch for 2 to 3 minutes, until bright green and just tender. Drain thoroughly using a colander and set aside.

Phase 03

Sauté Aromatics: In a large skillet over medium heat, melt 2 tablespoons unsalted butter. Sauté chopped onion until translucent, about 3 minutes. Add minced garlic and cook for 1 minute more.

Phase 04

Combine Filling Ingredients: In a large mixing bowl, combine sautéed onion and garlic, blanched broccoli, shredded cheddar cheese, sour cream, whole milk, condensed cream of mushroom soup, Dijon mustard, salt, and pepper. Mix until uniformly blended.

Phase 05

Assemble Casserole: Transfer broccoli mixture evenly into the prepared baking dish, spreading the top with a spatula.

Phase 06

Prepare Cornflake Topping: In a small bowl, mix crushed cornflakes with 2 tablespoons melted unsalted butter. Sprinkle evenly over the surface of the casserole.

Phase 07

Bake: Place baking dish in the oven and bake for 30 to 35 minutes, until the filling is bubbly and topping is golden brown.

Phase 08

Rest and Serve: Allow casserole to rest for 5 minutes before serving to set the filling.

Kitchen Tools

  • Large pot
  • Skillet
  • Mixing bowls
  • 9x13-inch baking dish
  • Measuring cups
  • Measuring spoons
  • Colander

Allergy Details

Always review ingredients for potential allergens and seek professional medical guidance if unsure.
  • Contains dairy: milk, cheese, and butter.
  • Contains wheat, present in condensed soup and cornflakes.
  • Check cornflake and soup labels for gluten if sensitive.
  • May contain traces of soy in processed ingredients.

Nutrition Details (per portion)

Values shown are estimates only - please consult healthcare providers for specific advice.
  • Energy: 320
  • Fats: 19 g
  • Carbohydrates: 25 g
  • Proteins: 13 g