Bring a small pot of water to a boil, carefully lower in the egg, and simmer for exactly 6 minutes and 30 seconds before transferring to an ice bath.
Cook the soba noodles in a separate pot of boiling water according to package directions, then drain and rinse with cold water to prevent sticking.
In a medium saucepan, heat the toasted sesame oil over medium-high heat and brown the ground pork until fully cooked and slightly crispy.
Stir in the minced garlic, fresh ginger, and shiitake mushrooms, sautéing for 2 minutes until the aromatics are fragrant.
Pour in the chicken broth, tamari, and sriracha, bringing the mixture to a gentle simmer.
Add the baby bok choy to the broth and cook for 1-2 minutes until the leaves are wilted but the stems remain tender.
Divide the noodles into a bowl, pour the pork and broth mixture over them, and top with the halved jammy egg and sliced green onions.