To make this dish, start by preparing the chicken. Cut the chicken thighs into bite-size pieces and add them to a bowl with the cornstarch. Toss to fully combine, then set it aside.
Next, prepare the sauce. Add all of the sauce ingredients (the soy sauce, toasted sesame oil, hoisin sauce, rice wine vinegar, mashed garlic, grated ginger, arrowroot flour or cornstarch, and coconut sugar or brown sugar) to a large measuring cup or mixing bowl. Whisk to fully combine, until the sauce is thick and there are no clumps.
Next, heat a pan, on the stove, over medium-high heat, and add in the avocado oil.
Once the oil is very hot (this is important), add in the chicken.
Allow the chicken to cook, undisturbed, for four minutes.
Then, scrape the pan, and toss the chicken, allowing it to cook for another 4-5 minutes.
Once the chicken is almost cooked through (and is brown, not pink), pour in the sauce and toss to fully coat the chicken in it.
Then, cover the pan, turn the heat to low, and allow the chicken to simmer in the sauce for another 10 minutes. Once it's done, turn off the heat, remove the cover, and stir the chicken in the sauce.
While the chicken is cooking, prepare the noodles according to the package instructions. Stir them frequently, so that they don't clump together.
Once the noodles are done, drain the water from them, rinse them under cold water, and set them aside.
Finally, assemble the dish by adding the noodles to the bottom of a bowl, followed by the chicken on top.
Garnish with sliced green onions and sesame seeds, then serve and enjoy!