Healthy Broccoli Casserole

This delicious, lightened-up Broccoli Casserole is a mash-up of broccoli and green bean casserole you will immediately love. It's made with tender-crisp broccoli tossed in a homemade mushroom gravy (no canned soup!) and topped with cheddar cheese and crispy onions. 

Growing up, my Mom made this amazing broccoli casserole that was basically a combination of frozen chopped broccoli, cheddar cheese, mayonnaise, and cream of mushroom soup, all covered in breadcrumbs. It was surprisingly delicious (given that ingredient list), but obviously, it isn't the healthiest and freshest recipe.

I knew I wanted to create a healthier version of this dish this holiday season. Usually, I would start from scratch to make this recipe, but let’s take a shortcut and get some inspiration from my absolute favorite: Healthy Green Bean Casserole.

I have been making this recipe for years, and it is seriously the best lightened-up casserole recipe. However, I wanted to change a few things to incorporate the cheddar cheese typically found in broccoli casserole.

It starts with fresh broccoli instead of frozen to retain as much crunch and texture as possible. That gets tossed with a creamy cheddar cheese sauce packed with mushrooms and plenty of garlic. Finally, everything is finished with another layer of cheddar cheese and tons of crispy red onions. So so good! No one will ever believe this tasty broccoli casserole is actually healthy.

I'm also dropping my recipes for Broccoli Macaroni and Cheese, Healthy Broccoli Cheese Soup, and Cheesy Broccoli Stuffed Chicken Breasts here because cheese + veggies are so good together!

Why You’ll Love Healthy Broccoli Casserole

• Make Ahead for Holidays: Assemble your broccoli casserole the night before and bake it the next day. This will take one dish off your cooking to-do list.
• No canned or frozen ingredients: We're making everything from scratch, from the thick cheese sauce to the fried onions and mushroom gravy. However, feel free to make this healthy broccoli casserole with cream of mushroom soup instead if that's more convenient for you.
• Crowd-friendly: This broccoli casserole is always the first to go during potlucks and gatherings. Even kids go for seconds!

Looking for more healthy holiday or Thanksgiving veggie side dishes? Don't miss this Whole Roasted Butternut Squash, Crispy Balsamic Brussels Sprouts, or Shaved Brussels Sprout Salad.

Ingredients and Easy Swaps

Here is everything you need to make this lightened-up broccoli cheese casserole:

• Broccoli: Unlike most broccoli casseroles, this recipe uses fresh broccoli florets so the final dish has some texture and crunch. No mushy casserole here. For more contrast, swap in some fresh cauliflower florets for some of the broccoli.
• Red onion: Red onion is milder than white or yellow onions. It also has a beautiful color. Feel free to swap in shallots, sweet Vidalia onions, or traditional yellow onions.
• Panko breadcrumbs: For the crunchy topping, Panko breadcrumbs are the perfect option. Use regular or whole wheat. Regular breadcrumbs or Ritz crackers also work, they just won't be quite as crisp. Gluten-free breadcrumbs or sliced almonds could also be used.
• Baby Bella mushrooms: Fresh mushrooms replace the condensed mushroom soup usually used in this casserole. Any mushroom can be used. This is great with button mushrooms, portobello, or a variety.
• Garlic: The garlic adds a nice punch of flavor to the dish. Fresh garlic is best but minced garlic or garlic powder can be used.
• Cheddar Cheese sauce: The cheese sauce in this recipe is made with whole wheat flour, chicken broth, milk, and cheddar cheese. Vegetable broth can be used for a vegetarian version.

How to Make Healthy Broccoli Casserole

It should go without saying, that this is the perfect dish for Thanksgiving or any holiday serving. Here’s how to whip up a healthy version that still feels festive and indulgent:

1. Blanch the broccoli: Start by blanching the broccoli florets in boiling water for 3-4 minutes until they are bright green and just beginning to soften. Immediately remove them from the boiling water and place them in an ice bath to stop them from cooking. The broccoli won't cook completely in the casserole so this step ensures it is completely cooked in the final product.
2. Make crispy onion topping: One of the best parts of this casserole is the crispy onion topping. Start by cooking the red onions in butter until they are tender but still have a bit of texture. Then cook the breadcrumbs in butter until they are nicely browned. Mix the browned, toasted breadcrumbs with the onions to make the topping.
3. Make the mushroom sauce: Start by sauteing the mushrooms in butter and garlic. Once they are tender, add the flour and cook for one minute. This helps to thicken the sauce. Then add the chicken broth and stir until the flour dissolves. Make sure it fully dissolves for a smooth sauce. Add the milk and half the cheddar cheese. Simmer gently, stirring often, until it thickens. Taste and season with salt and pepper as needed.
4. Assemble the casserole: Add the broccoli florets to a prepared casserole dish. Pour the mushroom sauce on top and stir to coat the broccoli in the sauce. Then add a layer of cheddar cheese and the crispy onions and breadcrumbs.
5. Bake: Bake the casserole at 375 degrees until the sides are bubbling and the onions are nicely browned. If needed, broil it for the last 2-3 minutes to get the top nicely browned.

Recipe Ideas

There are lots of ways to make this broccoli casserole unique and exactly what your family will love.

• Try a different cheese: Although I can't get enough of sharp cheddar cheese and broccoli, this will also work great with Parmesan cheese, pepper jack (for something spicy), Swiss, or any other cheese that melts well. You can also use a combination of cheeses. Basically, anything that would work in macaroni and cheese is perfect here.
• Add herbs or spices: Fresh herbs are a great addition to this dish. Dried herbs work great as well. Consider adding some thyme, rosemary, or Italian seasoning. You could also add some heat with red pepper flakes, smokiness with cumin, or extra flavor with onion or garlic powder. I find this works best when you add the herbs and spices to the mushroom sauce.
• Use a different vegetable: If you aren't feeling the broccoli, you can make this with cauliflower, green beans, or even butternut squash. Just make sure to par-cook any vegetable you use.
• Make it gluten-free: Just substitute gluten-free flour and breadcrumbs.
• Without onions: If you aren't a huge onion person, just leave them out. Top the casserole with a layer of cheddar cheese and toasted breadcrumbs.

Can I use frozen broccoli?

Frozen broccoli can be used instead of fresh, but the texture will be slightly different and a bit mushy. Start by cooking the frozen broccoli until just cooked. Immediately run it under cold water to stop the cooking. Dry it well to ensure your casserole isn't watery. Then use it as you would the fresh.

Can I add rice or pasta? What about chicken?

You can add some cooked rice, pasta, or chicken to turn this into a main course. If you plan to do this, double or triple the mushroom sauce. Then, fold the cooked pasta (cooked until al dente) or rice with the broccoli. If you like, you can also add cooked chicken.

What to Serve with Broccoli Casserole

This healthy broccoli casserole recipe will fit right into any holiday spread. It feels like a holiday meal but is easy enough for weeknight dinners. We like pairing it with these dishes in particular:

• Protein: This healthy broccoli mushroom casserole is a delicious side for any holiday main course like this Crockpot Turkey Breast or Stuffed Turkey Tenderloin. We also like pairing it with Slow Cooker Cranberry Pork, Baked Turkey Tenderloin, Herb Chicken Breast, and other lean proteins.
• Homemade bread: Serve your broccoli casserole with fresh-baked dinner rolls, garlic knots, bread sticks, or cheddar biscuits using my ridiculously easy Greek yogurt dough recipe.
• Salad: Cheesy broccoli casserole is quite rich, so it's nice to have something fresh like this Arugula Salad or Balsamic Spinach Salad to balance it out.
• Other sides: Complete your spread with other veggie sides. Parmesan Sauteed Peas, Honey Garlic Roasted Carrots, and Roasted Fingerling Potatoes are some of our go-tos during the holidays.

Storage and Reheating

Broccoli casserole is a dish that can be prepped the day before to make holiday meal prep easier. But leftovers also taste great the next day as long as you store and warm it up properly:

• To store: Cool your leftovers then transfer into an airtight container. It will keep for up to 3-4 days, but try to finish it before then for the best texture.
• To reheat: You can warm up your broccoli casserole in the oven or microwave. Cover with foil and bake at 350°F for 10–15 minutes, or microwave in 30-second bursts until hot.
• Make it in advance: Assemble the casserole and cover it with foil or plastic wrap and store it in the fridge. If possible, remove it from the oven 30-45 minutes before cooking to remove the chill. If not, just add 5-10 minutes to the baking time.