These Lentil Quinoa Veggie Burgers with Sweet Potato Fries are simply divine. With a lentil, quinoa and walnut blend, topped with caramelized onions, sweet potato fries and avocado slices, you will walk away full. Meat lovers will even fall in love with this mighty veggie burger.

Hello Wednesday! I know that grilling season is ramping up and becoming the go-to as the hot weather rolls in, but sometimes, we just need a good ol’ veggie burger. Enter Lentil Quinoa Veggie Burgers with Sweet Potato Fries. This one is particularly fabulous.
It’s loaded. I am mean seriously loaded. We’re talking lentils- bam, quinoa- bam, walnuts- bam, spices + fresh parsley- bam. We haven’t even gotten to the best part yet- homemade sweet potato fries AND caramelized onions. And fresh avocado! Whew, I’m going to need another burger after talking about it. Oh! And a simple spicy mayo mixture to slather on the burger buns. Yes, there are a few steps here, but you can break it up over a few days if you’d rather. Make the fries, caramelized onions, quinoa and lentils the day before. Then, rewarm the fries and onions before serving.
This is a super filling burger and my meat-loving husband has given it his highest praise. So definitely a win!

The process
This can be made in multiple steps, or you can do it all at once. Totally up to you.
To start, make the lentils and quinoa. Rinse both the lentils and quinoa. Bring the quinoa to a simmer with water and simmer until tender and cooked through. In a separate pot, cover the lentils with a couple inches of salted water (lentils are bland bland bland- salt helps a lot!). Simmer the lentils until they are cooked through and tender. Drain and set aside.
While the quinoa and lentils cook, make the fries and onions. Peel and slice the sweet potatoes into 1/2-inch spears. Toss with a little oil, salt + pepper. Spread out on to a pan and place in the hot oven. Cook until tender, golden or even a little dark brown (my favorite way to eat them is almost burnt). Set them aside.
For the onions, peel and thinly slice two onions. Heat oil in a heavy bottomed saucepan until shimmering. Stir in the onions and cook over medium heat, reducing to prevent burning. Stir often and cook for about 20 minutes, or until the onions are a deep golden brown. Set aside.

Now, in a small bowl, whisk together mayo and dried sriracha for a spicy mayo kick.
Next, place the cooked lentils, quinoa, walnuts, spices and fresh parsley in the bowl of a food processor. Pulse until the mixture is finely chopped and holds together when squeezed between your fingers. Scoop into 1/2 cup patties.
Heat some oil in a large frypan and place the patties in the hot oil. Cook, flipping once until the burger is a deep golden brown on both sides.

Assemble the burgers
It’s assembly time! Toast some burger buns until they are nice and crispy. Slather mayo on the inside of each half of the burger buns. Place a veggie burger patty on the bottom half. Top with caramelized onions, sweet potato fries and avocado slices. Serve and devour immediately.
This mammoth of a veggie burger will make meat lovers and vegetarians alike happy and satisfied. And full!


Notes & tidbits
You can make this over a few days if you don’t have the time to do this all at once. Simply make the veggie burger mixture a day or few days before and cook when you’re ready to eat. The fries and onions can also be made a day in advanced, just rewarm before serving on the burgers.
If the mixture isn’t holding together for whatever reason, pulse or stir in an egg when making the veggie burger mixture.



Lentil Quinoa Veggie Burgers with Sweet Potato Fries
These Lentil Quinoa Veggie Burgers with Sweet Potato Fries are simply divine. With a lentil, quinoa and walnut blend, topped with caramelized onions, sweet potato fries and avocado slices, you will walk away full. Meat lovers will even fall in love with this mighty veggie burger.
Ingredients
For the burgers
- 3/4 cup brown lentils, rinsed, drained, and picked through
- 1 cup quinoa, rinsed and drained
- heaping 1/2 cup walnuts
- 1 teaspoon ground cumin
- 1 teaspoon salt, plus more for salting water
- 1/4 teaspoon pepper
- 1/2 teaspoon dry sriracha
- 1/2 cup fresh parsley
For the sweet potato fries
- 2 large sweet potatoes, peeled and sliced into 1/2-inch spears
- 2 Tablespoons olive oil
- 3/4 teaspoon salt
- 1/2 teaspoon pepper
For the caramelized onions
- 2 medium onions, peeled and thinly sliced
- 1 Tablespoon grapeseed oil
For serving
- 1/2 cup mayo
- 1/2 teaspoon dry sriracha
- 2 avocados, thinly sliced
- 3 teaspoons grapeseed oil
- toasted hamburger buns
Instructions
- Place the quinoa in a medium saucepan and cover with 2 1/2 cups water. Bring to a simmer, reduce heat to maintain at a simmer and cook, uncovered until the quinoa is tender, about 20 minutes. Drain any water if necessary. Fluff with a fork and set aside.
- Meanwhile, place the lentils in a separate pot and cover with 2 inches of salted water. Bring to a boil, reduce to a simmer and cook uncovered until the lentils are tender and cooked through, about 15-20 minutes. Drain any remaining water and set aside.
- While the quinoa and lentils cool, make the sweet potato fries. Preheat the oven to 425ºF. Toss the sweet potato spears with the oil, salt and pepper. Spread out evenly on a large baking sheet. Place in the oven and bake, flipping at least once while cooking, until tender and golden, 20-25 minutes. Remove from the oven and let cool.
- To make the caramelized onions, Place a heavy bottomed skillet over medium-high heat. Drizzle in the oil and warm until shimmering. Stir in the onions and a pinch of salt, reduce heat and cook, stirring often, until golden brown, about 20 minutes. Reduce heat if onions begin to burn. Turn off from the heat and set aside.
- Place the lentils, quinoa, walnuts, cumin, salt, pepper, sriracha, and parsley in the bowl of a food processor. Pulse until the mixture is finely chopped and holds together when squeezed between your fingers.*
- In a small bowl, whisk together the mayo and sriracha. Set aside.
- Scoop the mixture into 1/2 cup sized patties*. Heat a skillet over medium heat with 3 teaspoons of oil. Place the patties in the skillet and cook until golden brown, flipping once, about 6-8 minutes on each side.
- To assemble, slather the inside of each toasted burger bun. Then, place a patty on the bottom half, top with caramelized onions, sweet potato fries and sliced avocado. Top with the other half of the burger bun and devour immediately.
Notes
*If you are having a hard time getting the mixture to hold together, pulse in an egg.
*The uncooked patty mixture can be refrigerated for a couple of days. Just cook up as needed when needed.
*If you would like to freeze the veggie burger mixture, scoop into desired sizes and wrap individually with plastic wrap and place in a freezer baggie. Thaw and cook as directed.
Nutrition Information:
Yield: 7 Serving Size: 1Amount Per Serving: Calories: 453
Nutritional information is only an estimate.