This is the gravy packet I use, Thai brand, Thai made, and it is quite good. And is low cost.
First thing we need to do is get the noodles cooking, so heat a pot of salted water to boiling, then add the egg noodles and boil until just tender. Drain.
I used a variant which adds a step here. I sauteed about 1 cup of sliced (Japanese Sogigiri or angle sliced) Shiitake mushrooms, and reduced the peas to 2 cups. After the mushrooms were sauteed, I just wiped out the pan and that is ready for the chicken now.
While the water is heating for the egg noodles, heat a non stick pan on medium heat with the oil, when hot add the chicken, season with salt and pepper as desired (I used white pepper), saute, turning them often.
When no pink is visible and they have released their water, as seen in the photo, remove and drain off the water, and set the pan aside. Don't over cook the chicken or you will have tough chicken. The will still cook when the pan is off the heat and you will have perfect tender chicken.
In a large sauce pan, prepare the gravy per the packet instructions, normally 1 cup water per packet, so 3 cups water and whisk in the 3 packets. When the gravy has thickened to your liking, reduce heat to a simmer and stir in the peas, and mushrooms if you prepared those.
Whens the peas are warmed through, takes just a few minutes, add the chicken and drained noodles, stir and let this simmer for a few minutes to heat everything through.
Serve and enjoy.