Step 1: Prepare Flax Egg - In a small bowl, combine the ground flax meal and water. Stir well and set aside for about 10 minutes to thicken. This will act as your binding agent.
Step 2: Sauté Aromatics - In a skillet over medium heat, add a splash of water or oil and sauté the chopped onion for about 3-4 minutes until translucent. Add the minced garlic and chopped mushrooms, cooking for another 5-7 minutes until the mushrooms are tender and browned. Stir in tamari and balsamic vinegar, cooking for an additional minute. Remove from heat and let cool.
Step 3: Mash Black Beans - In a mixing bowl, use a fork or potato masher to mash the black beans until mostly smooth, leaving some chunks for texture.
Step 4: Combine Ingredients - To the mashed black beans, add the sautéed mushroom mixture, oat flour, rolled oats, flax egg, fresh parsley, dried oregano, dried basil, and salt. Mix until well combined.
Step 5: Form Patties - With clean hands, divide the mixture into equal parts and shape them into patties. You should get about 4-6 patties, depending on the desired size.
Step 6: Cook the Patties - In the same skillet, add a bit more water or oil if needed and cook the patties over medium heat for about 5-7 minutes on each side, until they are crispy and golden.
Step 7: Assemble Your Burger - Toast your hamburger buns if desired. Layer your burger with lettuce, tomato slices, onion, avocado, and any other toppings you love. Drizzle with ketchup, BBQ sauce, or chipotle crema for extra flavor!