This easy and healthy vegetarian taco casserole with quinoa comes together with 15 minutes of prep time and 25 minutes in the oven! It relies on pantry staples to deliver bold Mexican flavors. Plus, you can serve the whole family with this recipe! Prep ahead and freezing instructions included.
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December is here, and it’s officially the most wonderful time of the year! But for many people, myself included, it’s also the busiest time of the year.
Our schedule is delightfully full at the moment. While I’m glad to have many fun events to look forward to this holiday season, it’s been difficult to keep up with food prep and cooking. I’m sure many of you are feeling the same way!
That’s why I’m sharing a super easy meal that’s perfect for busy weeknights in December (or any time of year). This vegetarian taco casserole is veggie-loaded, nutritionally balanced, and made with mostly pantry ingredients.
As if it wasn’t already easy enough, you can also prep my healthy Mexican casserole ahead of time, refrigerate or freeze, and pop it in the oven when you’re ready to eat. I’m smitten! And I hope you will be too.
How to Make Vegetarian Taco Casserole
For the full ingredients list and instructions, scroll down to the recipe card at the bottom of the post. In the meantime, here’s a preview of this easy recipe followed by my expert tips.
- Prepare ingredients. If you have not already made it, prep quinoa according to package instructions. Chop bell pepper and onion. Gather the other ingredients.
- Cook pepper and onion. Sautee the veggies in a skillet with olive oil and spices.
- Combine everything in a bowl. Mix together the quinoa, veggies, beans, corn, diced tomatoes (with their juices), and green chiles. Season with salt and pepper.
- Spread out the filling in a casserole dish and top with cheese. Bake until cheese is bubbly, add toppings of choice, and enjoy!
- To save time, prepare the quinoa in advance and keep it in the fridge until you’re ready to add it to the filling. Some grocery stores also sell frozen, microwaveable packets of quinoa. If you can’t make quinoa head of time, don’t worry. It doesn’t take long to cook (about 15 minutes) and can be made while you prep the other ingredients.
- Topping ideas include avocado, chopped cilantro, sour cream or Greek yogurt, salsa, tortilla strips, chopped tomatoes, and/or lime juice. It’s really delicious with any and all of these toppings!
- Possible substitutions include brown rice for quinoa, pinto beans for black beans, or a jar of salsa for diced tomatoes. You can also add cooked ground beef or turkey to the filling.
- Leftovers will last for 3 to 5 days in an airtight container in the fridge. Store leftovers separately from toppings. Reheat vegetarian taco casserole for 1 to 2 minutes in the microwave until warmed through. You can also reheat it in the oven in a baking dish for 15 minutes at 300 degrees F.
Prep Ahead and Freezing Instructions
You can make vegetarian taco casserole with quinoa a few hours ahead of time. Prep the filling, spread it in a baking dish, and add the shredded cheese. Cover and refrigerate. When you’re ready to bake it, uncover and increase the baking time to 30 to 35 minutes at 350 degrees F. Add toppings before serving.
To freeze this casserole, prepare it in a freezer-friendly casserole dish with lid (without the toppings). Freeze it for up to 3 months. When you’re ready to eat it, thaw in the fridge overnight then bake for 30 to 35 minutes at 350 degrees F. Alternatively, you can cook it from frozen and increase the baking time to 35 to 40 minutes.
If you love this vegetarian taco casserole with quinoa, check out the Lentil Tortilla Soup, Spaghetti Squash Burrito Bowls, and Healthy Chicken Fajita Bowls. For another easy casserole recipe, see the Healthy Tater Tot Casserole with Veggies.
I’d love to hear how you like this recipe! Rate/review using the stars on the recipe card or in the comments, and follow the Veg World on YouTube, Instagram, Facebook, and Pinterest. Looking for something totally different? Browse the recipe library.
Vegetarian Taco Casserole with Quinoa
- 1 cup uncooked quinoa - yields 2.5 cups cooked
- 1 tablespoon extra virgin olive oil
- 1 bell pepper - diced
- 1 yellow onion - diced
- 1 teaspoon chili powder
- ½ teaspoon ground cumin
- ½ teaspoon dried oregano
- 1 15-ounce can black beans - drained and rinsed
- 1 15-ounce can corn - drained and rinsed
- 1 14.5-ounce can diced tomatoes - with their juices
- 1 4-ounce can diced mild green chiles
- Salt - to taste
- Black pepper - to taste
- 1.5 cups shredded Mexican cheese - more for serving
- Toppings - avocado, tomatoes or salsa, sour cream, cilantro, lime, tortilla strips
- Preheat the oven to 350 degrees F. Grease a 9×13 (3-quart) baking dish and set aside.
- Prepare the quinoa according to package instructions if you haven't made it in advance. It usually takes about 15 minutes to cook, so get it going while you prep the rest of the ingredients.
- Warm the olive oil in a medium skillet over medium heat. Add the diced pepper and onion, and cook for 5 to 7 minutes until softened. Stir in the chili powder, cumin, and oregano, and cook for a few more minutes. Remove from heat.
- Transfer the peppers and onions to a large mixing bowl. Add the cooked quinoa, black beans, corn, diced tomatoes, and green chiles. Stir well. Season with salt and pepper to taste.
- Spread the quinoa mixture into the prepared baking dish. Sprinkle the shredded cheese on top.
- Bake the casserole for 20 to 25 minutes until bubbly. Add toppings of choice before serving. Enjoy!
- Leave a rating or review by tapping the stars on this recipe card (above) or in the comments section (at the end of the post)!
- Serving ideas: serve with a side salad or steamed vegetable
- Possible substitutions: brown rice for quinoa, pinto beans for black beans, jar of salsa for diced tomatoes
- Possible additions: cooked ground beef or turkey
- Make ahead: Prep the casserole (without the toppings) in the baking dish. Cover tightly with foil and keep in the fridge for a few hours. When you’re ready to bake it, uncover and increase the cooking time to 30 to 35 minutes.
- Freezing: Prep the casserole (without the toppings) in a freezer-friendly casserole dish with lid. Freeze for up to 3 months. Thaw in the fridge overnight before baking (bake time: 30 to 35 minutes) or bake from frozen (bake time: 35 to 40 minutes).
- Leftovers and reheating: Store in an airtight container in the fridge for 3 to 5 days. Reheat in the microwave for 1 to 2 minutes until warmed through or in a baking dish in the oven for 15 minutes at 300 degrees F.
- Nutrition facts do not include toppings.
Happy casserole eating! – Lizzie