Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Pat the chicken breast dry and cut into 1-inch cubes, then chop the broccoli into florets and the bell pepper into bite-sized pieces.
In a small bowl, whisk together the tamari, honey, toasted sesame oil, garlic powder, and ground ginger until well combined.
Spread the chicken and vegetables onto the prepared baking sheet, drizzle with olive oil, and season with sea salt and black pepper.
Roast for 15 minutes, then remove from the oven and pour the teriyaki sauce over everything, tossing to coat evenly.
Return to the oven for another 5-8 minutes until the chicken is cooked through and the sauce has thickened into a glossy glaze.
Sprinkle with sesame seeds before serving to add a delicate crunch.