Cut chicken breasts into bite sized pieces.
In a large wok, heat 1 Tablespoon vegetable oil. Add chicken carefully, and cook until no longer pink, about 7 minutes. Remove from wok and keep warm.
In the meantime, cook the noodles according to package directions.
Add the remaining 2 Tablespoons of oil to the wok. Bring to medium heat.
Add garlic and green onion and saute for just a few seconds; careful that the garlic doesn't burn.
Add soy sauce, chicken broth, brown sugar and chile-garlic sauce. Combine the cornstarch with ½ cup water and stir it into the sauce. Simmer sauce for about 2 minutes or until it thickens.
Once thick, add the chicken and simmer for an additional 5 minutes, until warmed through.
Place noodles on a serving plate and topped with chicken and sauce mixture. Serve and enjoy!