Mash the pinto beans with a fork or potato masher in a medium bowl. Add the cumin, garbanzo flour and parsley. Heat the oil and sauté the onion and garlic for 5 minutes, stirring frequently. Add the mushrooms and shoyu. Continue sautéing for another 3 to 4 minutes. Add to pinto beans along with the salt and pepper.
Shape the mixture into 4 (3-inch) patties. Heat the oil for frying the patties. Add the patties and fry about 3 to 4 minutes on each side or until crispy and golden. Serve on the buns with lettuce, tomato, mustard, and sauerkraut or your favorite condiments and toppings.
Per serving - 445 calories, 21 g fat (42% calories from fat), 14 g protein, 53 g carbohydrate, 10 g fiber, 0 mg cholesterol, 382 mg sodium