Bring a pot of water to a boil and cook the soba noodles according to package directions, then drain and rinse with cold water to prevent sticking.
In a small bowl, whisk together the tamari, rice vinegar, honey, toasted sesame oil, and red pepper flakes to create the stir-fry sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat.
Add the thinly sliced chicken breast to the hot pan and sear until golden brown and cooked through, then remove the chicken and set aside.
Add the broccoli florets and one tablespoon of water to the same pan, covering with a lid for 2 minutes to steam until they are bright green and tender-crisp.
Remove the lid and stir in the minced garlic and grated ginger, sautéing for about 30 seconds until highly aromatic.
Add the cooked noodles and chicken back into the pan, pour the sauce over the mixture, and toss everything together for 1 minute until the glaze is thickened and the dish is piping hot.