Begin by cooking the noodles according to the package directions.
In a large skillet heat a teaspoon of sesame oil and cook chicken until 165° or use precooked chicken.
Remove chicken from skillet and set aside.
Sauce 1-2 teaspoons of sesame oil with onion and garlic.
In a liquid measuring cup but combine chicken broth (or water and chicken bouillon) with soy sauce, oyster sauce, and spice (sriracha or crushed red pepper flakes) if using, with cornstarch
Slowly add sauce to a hot skillet stirring to heat and thicken.
Add carrots and pepper (and any other vegetable), and saute for 2 minutes or until vegetables are desired tenderness
Add in the cooked chicken.
Add pasta from the pot (reserving 1/2 cup liquid) and add noodles to the skillet.
Add liquid from noodles a little at a time until the desired amount of sauce is achieved to coat all the noodles well. add in the cooked chicken.
Adjust flavor by adding more soy/oyster sauce or adding more spice if using.
Serve with sliced green onion or cilantro.