Start making the dressing 30 minutes beforehand by coalescing brown sugar, sesame oil, soy sauce, rice vinegar and vegetable oil in a small jar that should have a tight fitted lid. After that shake all these ingredients well and then taste them. Add more of an ingredient which you think is less, according to your preference.
Take a frying pan and medium heat it. Now put in some tablespoons of vegetable oil and then break the noodles into bits in order to fry them in the pan. Soon the noodles will start puffing up. Remove and drain the noodles on a paper towel as they get puffed up.
Amalgamate chicken, lettuce, sesame seeds and spring onions in a large bowl, which should be put into the refrigerator to cool for about 10 minutes. After it gets chilled, add the noodles and the required amount of dressing before serving it. These ingredients should be tossed and mixed well. After tossing, serve this salad immediately in large bowls. You can use extra toasted sesame seeds for garnishing, if desired.