Prepare the Flax Egg: Mix the ground flaxseed with water in a small bowl and let it sit for 5 minutes until it becomes gelatinous.
Mix the Ingredients: In a large mixing bowl, combine the okara, cooked quinoa or brown rice, onion, carrot, flax eggs, parsley or cilantro, paprika, garlic powder, nutritional yeast, cumin, rice flour, and tapioca starch. Add optional nuts or seeds for extra crunch and nutrients.
Season: Add salt and black pepper to taste. Adjust any other seasonings as desired.
Form the Patties: Use your hands to form the mixture into burger patties. If the mixture is too wet, add more ground flaxseed or some rice flour to help bind it. If it's too dry, add some water.
Cook the Burgers: Heat a non-stick skillet over medium heat. To prevent sticking, add a small amount of water or vegetable broth. Place the patties on the skillet and cook for 5-7 minutes on each side until golden brown and firm.
Serve: The burgers can be served with some side dish on whole-grain buns or lettuce wraps with your favorite toppings, such as sliced tomato, onion, lettuce, and avocado.