Bring a medium pot of water to a boil and cook the soba noodles according to package directions, adding the chopped bok choy for the last 60 seconds of cooking. Drain and set aside.
In a small bowl, whisk together the tahini, tamari, rice vinegar, and chili oil until smooth; if the sauce is too thick, add a teaspoon of warm water to reach a creamy consistency.
Heat the avocado oil in a large skillet over medium-high heat. Add the ground turkey, breaking it up with a spatula, and cook until browned and cooked through.
Stir in the minced garlic, grated ginger, and crushed Sichuan peppercorns, sautéing for 1-2 minutes until the aromatics are fragrant and the turkey is well-seasoned.
Add the cooked noodles and bok choy to the skillet with the turkey, then pour the sesame sauce over the mixture.
Toss everything together until the noodles are thoroughly coated and heated through.
Garnish with thinly sliced scallions and serve immediately.