Prepare noodles per packet directions.
Heat oil in wok or large heavy based skillet over high heat. Add garlic and chili and cook for 10 seconds. Add onion; cook for 1 minute. Add chicken (if using), and cook 3-4 minutes.
In a small bowl, mix all the sauce ingredients until combined.
Add sauce, noodles and green onions to the pan and cook for 1-2 minutes until the sauce fully coats the noodles.
Remove from heat and immediately add basil, toss and serve immediately. Enjoy!