In a small bowl, whisk together the gochujang, tamari, sesame oil, honey, minced ginger, and minced garlic to create the glaze.
Bring a pot of water to a boil and cook the soba noodles according to package directions, then drain and set aside.
Slice the chicken breast into bite-sized pieces and season with sea salt and black pepper.
Heat avocado oil in a large skillet or wok over medium-high heat and sear the chicken until golden and cooked through, approximately 5-6 minutes.
Remove the chicken from the pan and add the broccoli florets and sliced red bell pepper, sautéing for 3-4 minutes until tender-crisp.
Return the chicken to the pan, pour the gochujang sauce over the mixture, and toss for 1 minute until the sauce thickens and coats everything evenly.
Serve the spicy chicken and vegetables over the cooked soba noodles, garnished with sliced green onions and sesame seeds.