Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Dice the chicken breast into uniform 1-inch cubes and chop the broccoli, bell pepper, and zucchini into bite-sized pieces.
In a small glass bowl, whisk together the tamari, honey, rice vinegar, minced ginger, and minced garlic until the honey is fully dissolved.
Place the chicken and chopped vegetables onto the prepared baking sheet, drizzle with avocado oil, and season with sea salt and black pepper.
Pour exactly half of the prepared tamari glaze over the chicken and vegetables, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture into a single layer and roast for 18-20 minutes, tossing halfway through, until the chicken is cooked and the vegetables are tender.
Remove from the oven, drizzle the remaining glaze over the hot chicken and vegetables, and garnish with sesame seeds before serving.