Drain the seaweed and preserve the water. Add their water into a medium soup pot, together with the 2 cups purified water, ginger and scallions, and bring to boil over medium heat.
Reduce the heat to low and add the ginger, garlic and drained seaweed. Cover with a lid and simmer for 10 minutes.
In a non-stick skillet heat the sesame oil and add the tofu cubes. Fry for 5-7 minutes, stirring frequently, until golden.
Turn off the heat for the soup, and add soy sauce, garlic, tofu and freshly ground black pepper.
Divide into serving bowls, garnish with diced scallions and serve warm.