Boil buckwheat noodles and rinse in cold water.
Mix perilla powder, anchovy broth, soy sauce, and salt to make the soup base.
Bring the soup base to a boil in a pot.
Place the cooked buckwheat noodles in a bowl and pour the hot perilla soup over them.
Top with garnishes (such as dried seaweed flakes and green onions) to finish.