Cheesy Mushroom and Broccoli Quinoa Casserole is a hearty yet meatless casserole recipe that's packed with veggies and decadent cheese!

When you’re in the thick of casserole season (read: it’s COLD outside!) but are looking for something on the lighter side, may I suggest Cheesy Mushroom and Broccoli Quinoa Casserole?
This hearty yet meatless meal is super satisfying without being too heavy.

What’s Inside
Sauted mushrooms, steamed broccoli, and fluffy quinoa are mixed with a homemade creamy mushroom sauce, plus an honorable amount of freshly shredded cheese then the mixture is baked until golden brown and bubbly.
Comforting, creamy, and just cheesy enough.
This recipe makes enough to feed five or six, but if you’ve got a smaller household, leftovers reheat beautifully.

Start by bringing 2-3/4 cups chicken broth to a boil in a small saucepan. Add 1-1/2 cups quinoa then place a lid on top, turn the heat down to low, and simmer until the liquid is nearly absorbed and the quinoa is tender, about 15 minutes.
Finally, add 2 cups finely chopped broccoli florets on top of the quinoa then place a lid back on top of the pan and let it sit off the heat for 10 minutes to steam.

While the broccoli and quinoa are cooking, start on the the homemade creamy (no cream needed!) mushroom sauce.
First melt 2 Tablespoons butter in a large skillet over medium-high heat then add 8oz sliced mushrooms, 1 chopped shallot or 1/4 onion, and salt and pepper. Saute the mushrooms until they’re golden brown then add 3 minced garlic cloves and saute for one more minute.

Add an additional 2 Tablespoons butter then, once it melts, sprinkle in 2 Tablespoons gluten-free flour (or AP flour if you’re not GF).

Cook while stirring for 1 minute then slowly stream in 1 cup each chicken broth and milk (any kind, though I do like 2% milk for homemade cream sauces) while whisking. Bring the mixture to a simmer while stirring constantly then turn the heat down to low and season generously with salt and pepper.
Simmer until the mixture is thickened and bubbly, about 5 minutes.

Add the quinoa and broccoli to the skillet along with 1-1/2oz each shredded sharp cheddar cheese and Monterey Jack cheese then mix until combined. Taste then add salt and pepper if needed.

Scoop the mixture into a nonstick sprayed 8×8 baking dish then top with an additional 1-1/2oz each cheddar and Monterey Jack cheese, and then bake for 15-20 minutes at 350 degrees, or until golden brown and bubbly.

Let the casserole sit and thicken for 10 minutes (if you can…my mousehole was created immediately,) then scoop, serve, and enjoy!


Ingredients
- 3-3/4 cup chicken broth, divided
- 1-1/2 cups quinoa, pre-rinsed
- 2 cups finely chopped broccoli florets
- 4 Tablespoons butter, divided
- 8 oz sliced mushrooms
- 1 shallot or 1/2 onion, chopped
- salt and pepper
- 3 cloves garlic, pressed or minced
- 2 Tablespoons gluten free flour, or AP flour if not GF
- 1 cup milk, any kind
- 3 oz freshly shredded Monterey Jack cheese
- 3 oz freshly shredded sharp cheddar cheese
Directions
- Preheat oven to 350 degrees. Spray an 8×8 baking dish with nonstick spray then place on top of a sheet pan (in case of spillovers) and set aside.
- Bring 2-3/4 cups chicken broth to a boil in a medium-sized saucepan then add quinoa, place a lid on top, turn heat down to low, and simmer until nearly all the liquid has been absorbed and quinoa is tender, 15 minutes. Add broccoli then place the lid back on top, remove from heat, and let steam for 10 minutes.
- Meanwhile, melt 2 Tablespoons butter in a large skillet over medium-high heat. Add mushrooms and shallots, season with salt and pepper, then saute until mushrooms are golden brown. Add garlic then saute for one more minute.
- Add remaining 2 Tablespoons butter then sprinkle in flour when melted and saute for one minute. Slowly stream in remaining 1 cup chicken broth and milk while whisking to avoid lumps. Season generously with salt and pepper then bring mixture to a simmer while stirring constantly. Turn heat down to medium then simmer until thick and bubbly, 5 minutes.
- Remove from heat then stir in the broccoli , quinoa, and half the cheese until smooth. Scoop the mixture into prepared baking dish then sprinkle remaining cheese on top then bake for 15-20 minutes, or until cheese is golden brown and bubbly. Let sit for 10 minutes before scooping and serving.
Nutrition
Nutritional values are estimates only. Please read our full nutrition information disclaimer.













I was hunting for a recipe that I had made with quinoa, broccoli and mushrooms and came across yours. I will make it for my vegan son for Thanksgiving. BTW, swapping the chicken broth for veggie broth will really make this a vegan recipe which is what I did with the recipe I couldn’t find.
Yours looks really good, like the other one I made so I’m sure he will enjoy it.
yum
O. M. G.!! I made this for dinner tonight. It was so incredibly good!!
My husband has declared this his favorite vegetarian meal. Thanks!
Made this for dinner and left the leftovers at my boyfriend’s house. Yesterday and today he’s texted me to let me know how excited he is to get home and eat dinner because there are still leftovers. So good!
Great dish! Even the toddler enjoyed it! Echoing others: cheeseburger version please!
This is so so good! Thank you!
This recipe looks delicious! I’m a pretty new cook so I was curious: If I wanted to add chicken to this recipe, would I add it before adding the mushrooms?
I would cook chopped chicken before the mushrooms then remove from the skillet, and then add back in with everything at the end.
Making this right now. Just tasted the mushroom sauce and that alone is good enough to slurp up with a spoon. Excited to get it all together.
Thanks
Love the meatless meals! Combined with mushrooms – sign me up!!
my kids arent the biggest quinoa fans – do you think i can just swap brown rice for quinoa? thanks!
I love meatless meals and love, love, love quinoa, mushrooms, and barley! It’s like you posted this just for me.
If you serve this as an entree, what side dishes would you serve outside of a green salad and crusty bread? Any ideas?