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.
Slice the chicken breast into thin, bite-sized strips and season evenly with sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat and sear the chicken until golden brown and cooked through.
Mince the garlic and grate the fresh ginger, then add them to the skillet along with the chopped baby bok choy.
Sauté the vegetables for 2-3 minutes until the bok choy stems are tender-crisp and the leaves are slightly wilted.
In a small bowl, whisk together the tamari, toasted sesame oil, and rice vinegar to create the sauce.
Add the cooked soba noodles and the sauce to the skillet, tossing everything together for 1-2 minutes until the noodles are well-coated and hot.
Remove from heat and garnish with thinly sliced green onions and toasted sesame seeds before serving.