Bring a pot of water to a boil and cook the soba noodles according to package directions, then drain and set aside.
In a large skillet over medium-high heat, cook the ground pork until browned and crumbled, about 5-7 minutes.
Add the minced garlic and grated ginger to the pork, sautéing for 1 minute until fragrant.
Stir in the baby bok choy and cook for 2 minutes until the leaves are wilted and the stems are slightly tender.
In a small bowl, whisk together the tahini, tamari, rice vinegar, chili oil, and water until a smooth, creamy sauce forms.
Pour the sauce over the pork and vegetable mixture, then add the cooked noodles and toss everything together to coat.
Garnish with sliced green onions and serve immediately.