Cook soba noodles according to package directions in boiling water, drain, and set aside.
Slice the chicken breast into bite-sized strips and season with sea salt and black pepper.
Heat the sesame oil in a large skillet or wok over medium-high heat.
Add the chicken to the skillet and cook until golden brown and cooked through, about 5-6 minutes.
Add the broccoli florets, sliced red bell pepper, minced garlic, and grated fresh ginger to the pan.
Stir-fry the mixture for 3-4 minutes until the vegetables are tender-crisp and aromatic.
Toss in the cooked soba noodles and tamari, stirring constantly to coat all ingredients evenly.
Garnish with sliced green onions and sesame seeds before serving hot.