Bring a saucepan of water to a boil and cook the Buckwheat noodles a few minutes. Drain and refresh under cold running water. Hold noodles in a bowl with cold water until ready to serve. Mix ginger, scallion and anchovy paste and set aside. In a small saucepan bring soy sauce, Mirin and vinegar to taste, to a boil. Mix this warm liquid into ginger, scallion and anchovy paste and season to taste with sugar, salt and pepper. Transfer this to 4 small dipping bowls. Drain noodles and portion out into 4 small bowls; top each portion with some julienned carrot. Toast sheet of Nori over an electric burner or place in a hot cast iron or heavy skillet and cook until crisp and crumble it over the soba and carrot. Dip noodles in sauce, and enjoy.