Bring a small pot of water to a boil. Gently lower the egg into the water and boil for 6 minutes and 30 seconds. Immediately transfer to an ice bath, peel when cool, and set aside.
Cook the soba noodles according to package directions until al dente. Drain and rinse under cold water to prevent sticking.
In a medium saucepan, heat the sesame oil over medium-high heat. Add the ground pork, sea salt, and black pepper, breaking it up with a spoon until browned and cooked through.
Stir in the minced garlic, grated ginger, and sliced shiitake mushrooms. Sauté for 2 minutes until fragrant.
Pour in the chicken bone broth, tamari, and sriracha. Bring to a gentle simmer.
Add the baby bok choy to the broth and cook for 2-3 minutes until the leaves are wilted and the stems are tender-crisp.
Place the cooked soba noodles in a deep bowl. Pour the pork, vegetables, and spicy broth over the noodles.
Slice the jammy egg in half and place on top. Garnish with sliced green onions before serving.