Soak seaweed in water to cover. When soft, drain, and cut into 2 inch pieces.
Heat a saucepan over medium heat; add beef, sesame oil, 1/2 tablespoon soy sauce, and a little salt, and cook for 1 minute. Stir in seaweed and remaining 1 tablespoon soy sauce; cook for 1 minute, stirring frequently.
Pour in 2 cups water, and bring to a boil. Stir in garlic and remaining 4 cups water. Bring to a boil, cover, and reduce heat. Simmer for 20 minutes. Season to taste with salt.