Prepare soba noodles according to package instructions and set aside.
Bring chicken broth to a boil in a large soup pot.
Meanwhile, wisk together scallions, sugar, ginger, chili garlic paste, vinegar, soy, mirin and sesame oil in a small bowl.
Once broth comes to a boil, add scallion soy mixture, sliced chicken breast and cabbage. Bring to a boil and let simmer for 3 minutes or until chicken is cooked through.
Divide soba evenly into 4 bowls and pour soup on top. Garnish with remaining scallions and serve with lime wedges, Sriracha, onion and cilantro if you wish.
Notes
Excellent source of Vitamins C and A, good source iron and calcium.