Bring a small pot of water to a boil. Carefully lower the egg into the water and boil for exactly 6 minutes and 30 seconds. Immediately transfer the egg to an ice bath, let cool, then peel and slice in half.
In the same pot, cook the soba noodles according to package directions until al dente. Drain and set aside.
Thinly slice the pork tenderloin into bite-sized strips and season with sea salt and black pepper.
Heat the toasted sesame oil in a medium saucepan over medium-high heat. Add the pork strips and sear until golden brown and cooked through, about 3-4 minutes. Remove pork from the pan and set aside.
In the same pan, add the minced garlic, grated ginger, and sliced shiitake mushrooms. Sauté for 2 minutes until fragrant.
Pour in the chicken bone broth and tamari. Bring to a gentle simmer, then add the baby bok choy and cook for 2 minutes until the greens are wilted but the stems remain crisp.
Whisk in the coconut milk and miso paste until the broth is smooth and creamy. Do not let the broth come to a hard boil once the miso is added.
Place the cooked noodles in a bowl and pour the creamy broth and vegetables over them. Top with the seared pork, the jammy egg halves, and sliced green onions.