Soak the seaweed in room temperature water until soft, about 15 minutes; drain. Rinse the sheets and cut into 2 inch long pieces; set aside.

Heat the sesame oil in a saucepan over medium-high heat. Stir in the beef, salt, and 1/3 of the soy sauce. Cook and stir until the beef is crumbly and no longer pink, about 4 minutes. Add the seaweed and the remaining soy sauce; cook and stir 1 minute. Stir in the garlic and pour in the water. Bring to a boil; reduce heat to medium-low and simmer until the beef and seaweed are tender, about 15 minutes more.