Boil a pot of water and cook the soba noodles according to package directions, then drain and set aside.
In a small bowl, whisk together the gochujang, tamari, rice vinegar, honey, minced garlic, and grated ginger to create the sauce.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat.
Add the diced chicken breast to the skillet and sear until golden brown and cooked through.
Toss in the broccoli florets and sliced red bell pepper, sautéing for 3-4 minutes until the vegetables are tender-crisp.
Pour the gochujang sauce over the chicken and vegetables, tossing well to coat everything evenly.
Add the cooked soba noodles to the skillet and stir for 1 minute until heated through and glazed.
Garnish with sliced green onions and sesame seeds before serving.