Prep the Beans: Preheat your oven to 375°F (190°C). Spread the black beans on a lined baking sheet and bake for about 15 minutes until slightly dried out.
Cook Quinoa: If you haven't already, cook the quinoa according to package instructions, then let it cool.
Prepare the Flax Eggs: Combine 2 tablespoons ground flaxseed with 6 tablespoons water and let it sit for about 15 minutes until it thickens.
Sauté Vegetables: In a non-stick pan, sauté the onion and bell pepper over medium heat with a bit of water to prevent sticking, until soft, about 5 minutes.
Process Dry Ingredients: In the food processor, pulse the ground oats, walnut pieces, garlic powder, onion powder, ground cumin, smoked paprika, black pepper, and a pinch of salt until mixed. Transfer to a large bowl.
Blend Beans and Vegetables: Add the slightly cooled beans, sautéed vegetables, and corn to the food processor. Pulse a few times until combined but still chunky for texture. Transfer this mixture to the bowl with the dry ingredients.
Mix the Burger 'Dough': To the large bowl, add the cooked quinoa, flax eggs, soy sauce, lime juice, and arrowroot or cornstarch. If using, add the chopped fresh herbs. Mix until well combined*.
Form Patties: Divide the mixture into 8 portions (1/2 cup of mixture). Shape each into a patty about ½ to 1 inch thick. You can refrigerate them for 30 minutes to firm up, making it easier to handle.
Cook the Burgers**: For Baking: Place patties on a parchment paper-lined baking sheet and bake at 375°F (190°C) for about 10 minutes on each side. For Pan-Cooking: Cook the patties in a non-stick skillet over medium heat for about 4-5 minutes on each side, until nicely browned and heated through.
Serve: Serve your black bean burgers with your favorite side, on whole-grain buns or lettuce wraps with your favorite toppings like avocado, tomato, lettuce, and a vegan sauce.
Storage: Leftover patties can be refrigerated for up to 4 or 5 days or frozen for longer storage.