In a large bowl, combine the water and bulgur; set aside for 30 minutes, or until the bulgur is soft. Place in a strainer and drain well, pressing out the excess water with the back of a spoon. Return the bulgur to the bowl. In a large no stick frying pan over medium heat, warm the stock. Add the onions, carrots, zucchini and thyme; cook' stirring frequently, for 4 to 5 minutes, or until the vegetables are tender and the liquid has evaporated. Add the the bulgur. Stir in the rice, egg, flour, walnuts, garlic powder, rosemary and pepper; nix well. Shape into 6 patties, adding more flour if the patties are too soft. Wash and dry the frying pan. Place it over medium heat and warm the oil. Add the patties and sauté for about 5 minutes per side, or until golden.