Cook soba noodles according to package directions, drain, and set aside.
Dice chicken breast into bite-sized pieces and season with sea salt.
In a small bowl, whisk together gochujang, tamari, toasted sesame oil, minced garlic, and grated ginger.
Heat avocado oil in a large skillet or wok over medium-high heat.
Add chicken to the skillet and sear until golden brown and cooked through, about 5-6 minutes.
Toss in broccoli florets and sliced red bell peppers, sautéing for 3-4 minutes until tender-crisp.
Pour the gochujang sauce over the chicken and vegetables, stirring constantly until the sauce thickens and coats everything evenly.
Fold in the cooked soba noodles and sprinkle with red pepper flakes for extra heat.
Garnish with sliced green onions and serve immediately.