Cover the seaweed with warm water in a bowl and let the pieces expand for 20 minutes. Rinse and drain. Put the sesame oil in a pan, add the meat and stir-fry over moderate heat for 1 minute. Add the seaweed and garlic and fry for another minute. Add the water, bring to a boil, and add the scallions. Simmer over low heat for 10 minutes. Serve.