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The Ultimate Bean & Mushroom Burger

This Ultimate Bean & Mushroom Burger passes the test! It won't fall apart and it's hearty, satisfying, smoky & bursting with rich umami flavor! (Vegan & gluten-free)
Course Entree
Cuisine Gluten-Free, oil-free option, Vegan
Prep Time 20 minutes
Cook Time 25 minutes
Total Time 45 minutes
Servings 8
Calories 293kcal


  • 2 1/2 tablespooons ground flaxseed + 5 tablespoons of water
  • 1 1/2 tablespoons olive oil (+ more for searing)
  • 1 small onion , finely diced (red or yellow)
  • 3 cloves garlic , minced
  • 12 ounces mushrooms , finely chopped (about 4 1/2 cups)
  • 1 teaspoon each of smoked paprika, cumin & oregano , more to taste
  • 14 ounce can white beans , drained well but not rinsed
  • 1 cup cooked rice (short grain is best)
  • 3/4 cup walnuts coarsely ground (I pulse them in the food processor)
  • 1 cup gluten-free rolled oats
  • 2 tablespoons gluten-free tamari , low sodium (sub soy sauce)
  • 1 tablespoon vegan worcestershire sauce
  • 1 tablespoon tomato paste
  • 1 1/2 teaspoons liquid smoke
  • Salt and fresh cracked pepper , to taste
  • 3 tablespoons arrowroot powder


  • In a small bowl, mix together the ground flax & water to make flax eggs. Set aside about 10 minutes. It will thicken up and become gel-like.
  • In a large bowl, mash the drained beans with a fork or potato masher. Add the rice, walnuts, oats, arrowroot powder, prepared flax eggs, tomato paste, worcestershire sauce, tamari & liquid smoke. Combine really well & set aside. 
  • In a large pan, heat the oil over medium heat. Sprinkle with salt. Sauté onion for 3-4 minutes, until translucent. Add garlic and sauté for 1-2 minutes.
  • Add the mushrooms turn the heat up to medium-high. Sauté until they release their liquid. Cook liquid completely off or there will be too much moisture. About 6-7 minutes. Now turn the heat back to medium and add the paprika, cumin & oregano. Sauté for 1-2 minutes. Remove from heat.
  • Transfer the cooked mixture into the large bowl of previously mixed ingredients. Combine well, using hands if necessary. Add cracked pepper and taste to see if it needs any more seasoning. Place mixture uncovered in the freezer for 25 minutes or the fridge for 45 minutes or more. This helps firm it up and meld the flavors a bit. 
  • Form the mixture into individual patties, keeping the size of the burger buns in mind. Create a ball with the mixture and place on a large piece of parchment paper. Now flatten evenly with your hands to create a 1/2" disc. Smooth out sides and any cracks with your hands. Repeat until the mixture is gone. * I used 1/2 cup of mixture to form 1/2" thick patties to fit a 3.5" burger bun. 

* For Baking: Preheat oven to 375 degrees F

  • Line a large baking sheet with parchment paper. * Optional: lightly spray with cooking oil for a crisper surface. Place in the oven for 16-18 minutes until lightly browned. Flip halfway through. When finished, remove from oven and let them cool for 5 minutes before handling (to let them firm up a bit). At this point, you can eat them, refrigerate or freeze them. 

* For searing:

  • Place 1-2 tablespoons of cooking oil in a large pan over medium heat. Make sure the oil is hot and shimmering before adding the uncooked patties (*The patties should sizzle when you place them on the pan). Don't overcrowd the pan or the patties will steam. Sear each side for about 3 minutes until crisp and brown. If you flip the patty to early, it will stick to the pan. It should lift up easier when the side is seared. Be gentle while flipping. Place them on a paper towel-lined plate and let them sit for 5 minutes to firm up. At this point, you can eat them, refrigerate or freeze them.
  • Spead vegan mayo on the burger buns. Dress burger with vegan cheese, lettuce, sliced tomato, red onion, pickles, mustard, and ketchup. Enjoy! 


* Cleaning Mushrooms: Use a damp paper towel or a soft brush to clean each mushroom. You can lightly rinse the mushrooms with water, but don't soak them. Pat dry when done. Mushrooms are like sponges and will absorb a lot of water, so I prefer the dry method.
* Sautéing Mushrooms: Mushrooms can produce a lot of water when heated. Use the largest pan you have to prevent overcrowding and steaming. Make sure it's nice and hot before adding the mushrooms to the onion. You should hear a little sizzle. Cook the mushrooms until they dry out a bit and release all their liquid. 
* I pulsed the mushrooms a few times in the food processor to get them finely chopped and make life easier. Be careful not to over process or they will be mushy. If you have a small processor, you may need to chop in two batches. 
* If at any point you feel the mixture is too wet or hard to handle, just add some oats, breadcrumbs or another 1/2 tablespoon of arrowroot powder. Another option is to grind up a few tablespoons of oats and add as needed. You can always pop it in the freezer for another 10 minutes too. * Be very gentle when handling the patties. 
* For easy flipping, use a thin and sturdy spatula. 
* If you only have whole flax seed, you can grind the seeds in a coffee grinder.
* These patties will store in the fridge for 5-7 days or the freezer for 2-3 months. Wrap them individually in wax paper and store them in a Ziploc or airtight container. 
* To reheat: Preheat your stove to 375 F. Place patties on a baking sheet and cook until heated through, flipping halfway. About 15-2o minutes. 
* Cook & prep time will vary depending on which method you choose. * Prep time doesn't include chilling time. 
* This article has great tips and tricks to keep your veggie burger from breaking apart. 


Serving: 1Patty | Calories: 293kcal | Carbohydrates: 46g | Protein: 11g | Fat: 6g | Sodium: 178mg | Potassium: 623mg | Fiber: 6g | Sugar: 2g | Vitamin A: 30IU | Vitamin C: 2.6mg | Calcium: 74mg | Iron: 3.5mg