top down shot of casserole with wooden serving spoon
Main Dishes,  Recipes,  Side Dishes

Broccoli Quinoa Casserole

August 20, 2025 /
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This healthy Broccoli Quinoa Casserole is delicious and comforting. Make it as a side dish for the holidays or for a simple weeknight dinner!

Casseroles are hearty, filling meals that often offer time saving convenience and are easy on your budget. I love a casserole because they are easy to prep. Then you can throw it in the oven and move on with your life. They make great leftovers and are easy to freeze. This recipe makes about 8 servings. We will usually eat about half and then freeze the rest for an easy weeknight meal some other time in the future.

vegan broccoli casserole overhead photo with serving on plate

What’s Special About This Casserole?

Casseroles hold a special place in the heart of Southerners. They are often served at family gatherings and special occasions. When my husband, Eric, was growing up his Mom would often make a broccoli rice casserole. This was something he looked forward to every year at Thanksgiving. This broccoli casserole is a little different than hers but still cheesy and delicious.

A traditional broccoli casserole is made from frozen broccoli, processed canned cream of mushroom soup, and gobs of mayonnaise. Our Broccoli Quinoa Casserole is better because it is made from fresh ingredients. There is no canned soup or mayonnaise in our casserole. Plus the addition of quinoa adds a protein punch! Quinoa has more nutrients and fiber than rice.

Serving Ideas

This casserole is hearty enough to be a main course, but it also shines as a side dish for holidays and gatherings. Here are a few ways to serve it:

  • A Complete Southern Spread: Pair this with Meatless Pinto Beans and Cornbread and a side of Collard Greens for a filling, protein-packed meal.
  • Holiday Side Dish: This is a fantastic, modern update to the traditional broccoli rice casserole. It pairs beautifully with holiday favorites like Southern Deviled Eggs.
  • The Potluck Favorite: Because this dish is easy to transport and stays warm for a long time, it’s a top-tier choice for parties.

Planning a get-together? This casserole is a lifesaver for gatherings! Check out my full guide to Vegetarian Southern Potluck Dishes for more transportable, crowd-pleasing recipes.

close up of vegan broccoli quinoa casserole with wooden serving spoon dipping into the dish

Frequently Asked Questions

Can I use rice instead of quinoa?

Yes! While this recipe uses quinoa for its added protein and fiber, you can certainly substitute it with cooked white or brown rice. If using rice, ensure it is fully cooked before mixing it with the cheese and vegetables.

If you are looking for a Broccoli and Rice recipe try my Homemade Cheddar Broccoli Rice-A-Roni (Better Than the Box!) for an easy weeknight dinner.

Should I use fresh or frozen broccoli?

I recommend using fresh broccoli chopped into small pieces for the best texture. However, you can use frozen broccoli in a pinch. Just be sure to thaw it completely and pat it dry with a paper towel to prevent the casserole from becoming watery.

Can I make this dairy-free or vegan?

Easily! You can use a plant-based milk (almond milk works great here) and a vegan cheddar cheese alternative. Since the base of the sauce is a simple roux made with flour and butter, just swap the butter for a vegan butter substitute.

Why is my quinoa still crunchy?

Quinoa usually stays crunchy if it hasn’t absorbed enough liquid or hasn’t simmered long enough. Make sure you follow the instructions to let the quinoa sit with the lid on for at least 5 minutes after boiling. This “steaming” phase is crucial for a fluffy texture.

How do I store and reheat leftovers?

  • Fridge: Store in an airtight container for up to 4 days.
  • Freezer: This casserole freezes beautifully! Wrap it tightly and freeze for up to 3 months.
  • Reheating: Reheat in the oven at 350°F to maintain the cheesy texture, or microwave individual portions with a splash of water to keep the quinoa moist.
top down shot of casserole with wooden serving spoon
5 from 2 votes
Print

Broccoli Quinoa Casserole

Course Dinner, Main Course
Cuisine Southern, Vegetarian
Keyword Broccoli, Quinoa
Prep Time 10 minutes
Cook Time 1 hour 30 minutes
Total Time 1 hour 40 minutes
Servings 8

Ingredients

  • 1 cup Quinoa
  • 2 cups Vegtable Broth
  • 4 cups Broccoli Chopped into small pieces
  • 1 Yellow Onion Finely Diced
  • 1 tbsp Olive Oil
  • 2 tbsp Butter
  • 2 tbsp All Purpose Flour
  • 2 tbsp Dijon Mustard
  • 2 cups Milk Plant milk works well in this recipe
  • 8 oz Shredded Cheddar Cheese Freshly grated in food processor
  • 1/2 tsp Thyme
  • 1/4 tsp Sage
  • 1/4 tsp Salt
  • 1/4 tsp Black Pepper

Instructions

  1. Add 1 cup of quinoa and 2 cups of vegtable broth to a small pot. Bring the mixture to a boil over medium high heat. Once boiling reduce the heat, cover with a lid and simmer.

  2. After simmering for 15 minutes remove the pot from the heat and set to the side with the lid on for at least another 5 minutes.

  3. Pre heat the oven to 350.

  4. In a large skillet sauté the diced onions in a tablespoon of olive oil. Cook for 8 minutes stirring occasionally.

  5. Then add the chopped broccoli. Sauté with the onions for a few minutes to soften the broccoli.

  6. Season the onions and broccoli with thyme, sage, salt, and pepper.

  7. Add 2 tablespoons of Dijon mustard and stir to combine.

  8. Add the 2 tablespoons of butter. Stir until melted. Then sprinkle 2 tablespoons of flour over the onions and broccoli. Stir well to coat the veggies with the flour.

  9. Slowly pour in 2 cups of milk and continue to stir. Plant milk works well in this. We used almond milk.

  10. Allow the milk to simmer and thicken for just a minute or two. Then remove from the heat.

  11. In a large mixing bowl combine the cooked quinoa, onion and broccoli mixture, and the shredded cheddar cheese.

  12. Pour your mixture into a casserole dish and bake for one hour.

Looking For Other Casserole Recipes?

Try one of these Breakfast Casseroles! Our Everything Bagel Vegetarian Breakfast Casserole is perfect for your next brunch because all the work is done the night before so all you have to do in the morning is pop it in the oven. If that doesn’t do it for you maybe check out our Easy Vegetarian Breakfast Casserole.

Looking for a potato casserole? Try our Vegan Potato and Collard Greens Casserole or this Cheesy Mashed Potato Casserole.

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