In a mortar, pound the garlic and chilis with a pestle until fine.
Add 1 ½ tablespoons of fish sauce, 3 tablespoons lime juice, and 1 ½ tablespoons of granulated sugar to the garlic and chili mixture.
Dissolve the sugar by stirring with a spoon. Set the dressing aside.
In a bowl mix the ground chicken with a pinch of salt and a pinch of pepper.
Cook the chicken with about ½ cup of water in a pan. Use a spatula to break it into small pieces. Set aside when done.
Cook the noodles in boiling water for 2 minutes and drain.
To a large bowl, add the cooked noodles, chicken, onion, tomato and green onions. Pour the salad dressing over and mix well. Sprinkle with chopped cilantro and serve.