First make the sesame noodles: Cook the spaghetti according to package directions. Rinse and drain.
In a jar, add the soy sauce, sesame oil and the sugar. Shake until well blended and the sugar has dissolved. Pour this over the pasta.
Toss with scallions and sprinkle with the sesame seeds. Set aside while you marinate and then cook the chicken.
Chicken: In a bowl mix the soy sauce, teriyaki sauce, garlic, brown sugar and the ginger. Make sure the sugar has pretty much dissolved. Add the chicken, making sure it's all coated with the sauce. Cover and stick in the fridge for 2-3 hours.
Remove the chicken from the marinade, and toss out the marinade left at the bottom of the bowl.
Heat the sesame oil in a large non-stick pan.
Add the chicken in batches and sauté for about 10 minutes, or until done, adding more sesame oil as needed.
Remove the chicken from the pan and let cool slightly. Slice the chicken diagonally into thin strips.