Step 1: Prepare the Flax Egg

• In a small bowl, combine the ground flaxseed and water. Stir the mixture well and let it rest for approximately 10 minutes, or until it becomes thick and gel-like.
  2 tbsp ground flaxseed, 5 tbsp water

Step 2: Cook the Onion and Mushrooms

• Heat 1 tablespoon of olive oil in a large skillet over medium heat.
  1 tbsp olive oil
• Add the diced onion and chopped mushrooms and cook them for 8 to 10 minutes, stirring occasionally. Continue cooking until the mushrooms have released their moisture and become deeply browned.
  1 sm yellow onion, 8 ounces cremini or Baby Bella mushrooms
• Add the minced garlic and cook for another 30 seconds.
  1 clove garlic
• Remove the skillet from the heat and allow the mushroom mixture to cool completely before combining it with the remaining ingredients.

Step 3: Combine the Burger Ingredients

• Transfer the cooled mushroom mixture to the bowl of a stand mixer fitted with the paddle attachment.
• Add the black beans, brown rice, quick oats, flour, prepared flax egg, vegan Worcestershire sauce, barbecue sauce, smoked paprika, umami seasoning, sea salt, and black pepper.
  1 15 ounce can black beans, 1 cup cooked brown rice, ½ cup quick oats, ⅓ cup all-purpose flour, 1 tbsp vegan Worcestershire sauce, 2 tbsp barbecue sauce, 2 tsp smoked paprika, 1 tsp Trader Joe's Umami Seasoning, ½ tsp sea salt, ¼ tsp freshly ground black pepper

Step 4: Mix the Burger Mixture

• Mix everything on low speed until the ingredients are evenly combined.
• I like to leave some texture from the beans, rice, and mushrooms rather than mixing everything into a completely smooth paste.
• The mixture should hold together when I press a small amount between your fingers.

Step 5: Allow the Mixture to Rest

• Allow the burger mixture to rest for 10 minutes so the oats can absorb any excess moisture.
• If the mixture still feels too wet to shape, add another 1 to 2 tablespoons of quick oats.

Step 6: Shape the Patties

• Using a large ice cream scoop, portion the mixture into 10 equal-sized mounds and place them on a parchment-lined baking sheet.
• Gently flatten each mound with my hands to form a patty approximately ¾-inch thick.

Step 7: Chill the Burgers

• Refrigerate the shaped patties for at least 30 minutes. This helps the burgers become firmer and prevents them from falling apart while they cook.

Step 8: Cook the Burgers

• Heat 1 to 2 tablespoons of olive oil in a large skillet over medium heat.
  1 to 2 tbsp olive oil
• Working in batches when necessary, cook the burgers for 4 to 5 minutes per side, or until they are golden brown, crisp on the outside, and heated through.
• Avoid moving the patties too soon. Allowing the first side to develop a good crust makes them much easier to flip.

Step 9: Make Christine’s Burger Sauce

• While the burgers are cooking, whisk together the vegan mayonnaise, yellow mustard, dill relish, and prepared horseradish or Tabasco sauce in a small bowl.
  2 tbsp vegan mayonnaise, 1 tbsp yellow mustard, 2 tsp dill relish, 1 tsp prepared horseradish or a few dashes or Tabasco sauce
• Taste the sauce and add a little more horseradish or hot sauce when I want an extra kick.

Step 10: Assemble and Serve

• Serve the burgers on toasted pretzel buns with Christine’s Burger Sauce and all your favorite toppings.
  Toasted pretzel buns, Crisp Lettuce, Sliced Tomatoes, Thinly sliced red onion, Sliced avocado, Pickles, Vegan Cheese, Additional barbecue sauce
• For a lighter option, serve the patties in lettuce wraps or crumble them over leafy greens with tomatoes, avocado, red onion, pickles, and extra vegetables.