Bring a pot of water to a boil and cook the soba noodles according to package directions, adding the chopped bok choy during the last 60 seconds of cooking.
In a small mixing bowl, whisk together the tahini, tamari, chili oil, rice vinegar, and water until the sauce is smooth and pourable.
Heat a large skillet over medium-high heat with the toasted sesame oil and add the ground turkey, breaking it apart with a spatula until browned and cooked through.
Stir the minced garlic, grated ginger, and ground Sichuan peppercorns into the turkey and cook for 1 minute until highly fragrant.
Drain the noodles and bok choy, then transfer them directly into the skillet with the seasoned turkey.
Pour the prepared sesame sauce over the noodle mixture and toss thoroughly to ensure everything is evenly coated.
Divide into a bowl and garnish with freshly sliced green onions before serving.