A cheesy and utterly delicious vegan quinoa casserole that’s loaded with veggies and flavour! It’s wholesome, melty, filling, and incredibly satisfying. Prepare it in advance and pop it in the oven before serving!
This recipe was originally published in March 2020. It has been updated for content and photos.
While a good warming casserole dish is best in colder months, this one is super satisfying to enjoy all year long.
And just like our enchilada casserole, this dish is loaded with veggies and delicious flavours.
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Ingredients + Substitutions
Here’s what you’ll need to make this yummy vegan quinoa casserole.
For the casserole base
- Lentils: Split red lentils work well because they are binding and help hold everything together to slice and serve. You may use another lentil variety or even black beans if preferred.
- Quinoa: This superfood is naturally gluten-free, it’s filling and is a great source of added protein to our quinoa bake.
- Veggies: I’m using leek, zucchini, and mushrooms, but this dish would work well with other veggies too. Try onion, bell peppers, tomatoes, green beans, peas, broccoli, corn, or whatever you have on hand. If you don’t have fresh produce available, frozen works too.
- Spices: Garlic powder, dried thyme, and salt. But feel free to add more seasoning to your taste. Cumin, smoked paprika, oregano, chili powder, and/or cayenne pepper would make great additions as well.
For the vegan cheese sauce
- Sweet potato: Adds additional nutrients and vegetables to our vegan quinoa casserole. Plus, its natural orange colour makes it rich and visually appealing. Butternut squash is a great alternative if you don’t have sweet potatoes available.
- Oats: Use certified gluten-free, if needed. The oats give our cheese sauce a thicker texture.
- Nutritional yeast: For cheesy flavour.
- Tapioca starch: Gives the dairy-free cheese sauce its melty and stretchy texture, but if you don’t have any on hand, you may use cornstarch or brown rice flour with similar results.
- Apple cider vinegar: For a touch of tang that any good cheese sauce needs. If you don’t have any on hand, lemon juice or lime juice works as well.
- Spices: Onion powder, smoked paprika and salt get added to our cheese sauce to enhance its flavour. For spice, add a dash of hot sauce or cayenne pepper.
Instructions
(This is a summary with step by step photos, full recipe measurements and instructions are in the recipe card below.)
Start by preheating your oven and getting your lentils and quinoa cooking in a sauce pot with the broth. Once cooked, set it aside.
NOTE: I like using vegetable broth to cook my lentils and quinoa for added flavour. But salted water works too if you don’t have any on hand.
At the same time, add the diced sweet potato to a small pot covered with water and let that boil until fork tender. Drain and set aside until you’re ready to make the cheese sauce.
Meanwhile, sauté the leek, zucchini, and mushrooms in a pan over medium heat. (photo 1)
Add the cooked lentils and quinoa to a baking dish and the sautéed veggies on top. (photo 2)
NOTE: You shouldn’t need any oil or water since the mushrooms will release a lot of moisture, but make sure to stir often to prevent sticking.
Mix everything well to evenly distribute the veggies throughout. (photo 3)
Add all the cheese sauce ingredients to a blender and process until smooth. (photo 4)
Evenly pour the cheese sauce over the casserole mixture. (photo 5)
Bake in your preheated oven for 15-20 minutes. (photo 6)
Serve hot and enjoy!
Storage
This vegan quinoa casserole tastes best when fresh out of the oven as the cheese will be warm and melty. As it cools, the cheese sauce will start to harden some, but will still taste great!
To return the cheese to a melty state, pop it back in the oven to reheat.
Leftovers keep refrigerated for up to 4 days. You may reheat in the oven and enjoy.
Can I make it in advance?
You may fully prepare and assemble this dish in advance. Refrigerate your unbaked casserole 1-2 days before baking.
Then, when ready to bake, just pop it in the oven and you can have dinner on the table in 20 minutes.
Expert Tips
- Cook the quinoa and lentils in a delicious broth (instead of water) for added depth of flavour.
- Prep and assemble the casserole in advance if possible. Then you can have dinner on the table in 20 minutes on those busy weeknights.
- This vegan quinoa casserole tastes best when freshly baked and the cheese sauce is hot and melty. As it cools down to room temperature, the cheese layer will begin to harden. To return it to a melty state, just pop it back in the oven and reheat it.
More delicious vegan casserole recipes
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Buon appetito
Rosa
📖 Recipe
Ingredients
- 1 cup split red lentils
- ½ cup quinoa
- 4 cups low sodium vegetable broth
- 1 ¼ cup leek finely chopped
- 1 cup zucchini diced
- 8 ounce (227g) package button mushrooms chopped
- 1 teaspoon garlic powder
- ½ teaspoon dried thyme
- ½ teaspoon sea salt or to taste
For the Cheese Sauce
- 1 cup sweet potato cubed
- ⅔ cup rolled oats gluten free if preferred
- ¼ cup nutritional yeast
- 3 tablespoons tapioca starch or tapioca flour
- 1 cup water
- 1 teaspoon apple cider vinegar
- 2 teaspoon onion powder
- 1 teaspoon smoked paprika
- 1 teaspoon sea salt
- Optional Garnish: thyme
Instructions
- Preheat your oven to 450°F/232°C.
- In a medium sauce pot, add your lentils, quinoa and veggie broth and bring to a boil. Reduce heat, and let simmer uncovered for 20 minutes stirring occasionally, until liquids are mostly absorbed. (Towards the end of cooking, stir more often.) Set aside.
- Meanwhile, add your diced sweet potato to a small pot, covered with water, bring to a boil and cook until fork tender, approx. 8 minutes. Drain and set aside.
- To a large skillet, add the leek, zucchini, mushrooms, garlic powder, thyme, and salt and sauté over medium-high heat until softened, approx 5 minutes. Stir often to prevent sticking. You should not need any water or oil since the mushrooms will release moisture as they cook.
- Add the cooked quinoa and lentils, plus the sautéed veggies to a 9"x13" (or similar) baking dish and mix well.
- To make the cheese sauce, add your cooked sweet potato, and all remaining cheese sauce ingredients to your blender and process until smooth. Evenly pour the sauce over your lentil, quinoa, and veggie mixture, and sprinkle with more thyme, if you'd like.
- Cover the dish with parchment paper and then aluminum foil and bake for 15 minutes. Then remove the foil/paper and bake another 5 minutes to slightly brown the top. Serve hot.
Cheryl says
This was a hit!! Next time I will add more veggies but that is just my preference. Will make again.
Rosa says
So glad you enjoyed it Cheryl. 🙂
LuAnn says
This is delicious! I made it exactly as shown. It came out perfect!
Rosa says
Thrilled you enjoyed it LuAnn!
Sandra White says
What is tapioca starch? or is there a substitute?
Can I use green onions or reg. onions instead of leeks?
Love your recipes…..the easy ones with few steps or ingredients I love the most.
Rosa says
Hi Sandra, tapioca starch is a unique thickener that makes the cheese creamy and “melty”. You may use cornstarch or flour with similar results. Onions are fine instead of leeks. Enjoy.
Annemarie says
Hi Clare. I’m looking forward to this for a dinner. Can I make make and put this together but leave in the fridge till it’s time to bake? Thank you kindly. Annemarie
Rosa says
Sure, that works. Might need a bit longer to heat through.
Clare says
I’m from England and do not understand what a cup measures can you tell me what the measurements are in ounces or grams?
Rosa says
Hi Clare, 1 cup is equal to 8 fluid ounces in the UK. Hope you enjoy the recipe.