Vegan “veggie supreme” Pizza Quinoa Casserole! All the delicious flavors of your favorite pizza… in healthier quinoa casserole form!

I thought it might be fun for two of my favorite things (pizza + quinoa) to join forces. And I decided to go all-in with a “veggie supreme” using garlic, onion, mushroom, tomato, spinach, and green pepper.
We were even treated with the wonderful smell of pizza as it baked! (It’s definitely worth noting that the leftovers make a great take-along lunch.)

Although the recipe calls for a 15 oz. can of tomato sauce, we only used about 10-12 oz. to our taste. I’d suggest starting with less and add more as you like. Or feel free to substitute 1-2 cups of your favorite marinara sauce for the tomato sauce, and tweak the seasonings from there.
Fresh basil makes a great garnish before serving!

Vegan Pizza Quinoa Casserole
Ingredients
- 1 1/2 cups white quinoa (uncooked)
- 1 onion
- 1 green bell pepper
- 8 oz. sliced mushrooms
- 3 roma tomatoes (or grape/cherry tomatoes)
- 1 cup fresh spinach
- 3 cloves garlic
- 15 oz. can tomato sauce (or less to taste)
- 1 cup vegan mozzarella shreds (Miyoko's, Follow Your Heart, etc.)
- 1 tsp. dried basil
- 1/2 tsp. dried oregano
- Salt to taste
Instructions
- Preheat oven to 375°F (190°C).
- Cook quinoa: in a saucepan, add rinsed quinoa and 3 cups water (or veggie broth for more flavor). Bring to a boil, cover, reduce heat, and simmer for 15-20 minutes or until liquid is absorbed.
- Meanwhile, chop onion, green pepper, and tomatoes. Mince garlic.
- In a skillet over medium heat, saute onion, green pepper, and sliced mushrooms with salt for about 10 minutes or until softened. (I use 3 Tbsp. water/broth for no-oil saute method.)
- Add garlic, stir, and saute 1 more minute.
- When quinoa is cooked, place it in a large mixing bowl. Add tomato sauce, tomatoes, spinach, mozzarella, sauteed vegetables (any excess liquid removed), basil, and oregano. Stir to combine.
- Spread mixture into a 9×13 inch baking dish (lightly sprayed if desired) and gently press down. Top with a light sprinkle of cheese if desired.
- Bake for 20-25 minutes. Garnish with fresh basil if desired.
Notes
Nutrition Per Serving (Estimate)

Enjoying this vegan pizza quinoa casserole? Also check out:
Come join The Garden Grazer on Instagram and then share a photo if you make or adapt this! (Also please leave a review & star rating below if you give it a try. Your feedback is greatly appreciated – thank you!)
Looks delicious!!!!
Thanks Courtney!
brilliant idea! looks amazing!
Thank you!
This is a great way to cook quinoa! I am surely going to make this!
Thanks! Hope you enjoy 🙂
Hi:) this looks great, just wondering when you sauté the vegetables should there be oil or just salt? Thanks 🙂
Hi Robyn! You can add a tiny bit of oil to sauté, or simply do a “no-oil sauté” by using 3 Tbsp. vegetable broth or water!
Thanks Kaitlin:)
I think this will be my dinner tonight! I'm so excited!
So great – hope you enjoy Brittany!
I really like the sound of a pizza quinoa casserole!
Thanks Kevin! 🙂
I was able to serve this for my carnivore husband and picky 17 year old son. It was enjoyed by all.
Wonderful to hear that, Ann!
What can be substituted for onion and garlic? I am finding lots of recipes that use these seasonings and finding it hard to adapt. thought maybe you might have an idea.
Hi! Onion and garlic are ingredients that provide lots of flavor, so I agree it’s tough to find a substitute. Have you tried leeks, green onion, or shallots? They’re milder but could still work. (Or do you suffer from allergies that don’t allow you to eat anything in the onion/garlic family?)
Oh my word this is TASTY!!! Just made it for dinner (we do eat a lot of vegetarian dishes in our house) and it is FABULOUS!! Since there are only two of us, it made enough for 3 dinners for us and 3 lunches for my husband. LOVED it!
So great to hear that, Mary! Thank you for sharing!
Made this last night. LOVED it. Thank you so much. My husband likened it to lasagna!!! lol.
So great! Glad it was a success for you!
Discovered your website tonight…I am a big fan already! Cannot wait to try your recipes!
Hi Amanda! Thank you! Hope you enjoy any recipes you try 🙂
Can this be frozen before baking???
I haven’t personally tried that yet, but I’m guessing it would do very well as a freezer meal! Would love to hear if you try it.
I'm totally going to try this – MINUS the cheese! Great idea! Thanks!
Awesome Heather! Enjoy!
My favorite thing about your blog is that you post recipes with a lot of ingredients I usually have on hand anyway…but find such a creative way of putting them together! One day it's Asian, next it's Mexican (similar ingredients, just with switching up the sauces/way it's made). Cost efficient and delicious 🙂
Hi CJ! Thank you so much for your sweet and thoughtful comment. So glad you’re enjoying the recipes 🙂
You had me at Pizza Quinoa!
Haha – two magical foods collide 🙂 Hope you enjoy!
Googled a quinoa and broccoli casserole and discovered your site. Loved it! Just took the pizza casserole out of the oven. Smells delicious. Will definitely use your site a lot more…and I have already recommended it to friends! Thank you 🙂
Hi Colleen! So great to hear and thank you so much for recommending it to friends!
WOW! This is so incredibly tasty!!! I have a severe dairy allergy so I had to substitute with vegan cheese, but this was such a treat!!!!!!!! I haven't had pizza in years and this truly captures the flavor! Thanks for the recipe!!!
Hey Chelsea! So great to hear!
Hello! I was wondering how many servings this recipe makes?
Hey Sara! I’d estimate about 8 medium bowls 🙂 Hope you enjoy!
Kaitlin, I made this tonight, with a serious tweak! I love quinoa, but my next marathon is coming up one week from today, so this week is all about carbs! While I know quinoa is a very healthy source of carbs, I am craving pasta (rungry!) so I made Pasta Pizza Casserole ala The Garden Grazer! I kept your recipe but subbed whole grain & brown rice pasta (had smaller portions of both, so mixed..) using my favorite vegan mozzarella from Trader Joe's (has a slightly sweet/smoky taste) and it was soooooooo good! I'll definitely be making this again with quinoa and also with pasta! Thanks as always for your inspirations! Sorry, no picture this time, too "rungry" and had to eat it asap! 🙂
This is awesome Terri! What a great substitution! Thank you for sharing your adaption and hope the marathon went well! -Kaitlin