Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Cut the chicken breast into bite-sized cubes and place them on the baking sheet along with the broccoli florets.
Drizzle the chicken and broccoli with olive oil, sea salt, and black pepper, tossing well to ensure even coating.
Spread the ingredients into a single layer and roast for 15-18 minutes until the chicken is cooked through and the broccoli is tender.
While the chicken roasts, combine the orange juice, tamari, rice vinegar, honey, grated ginger, minced garlic, and arrowroot powder in a small saucepan.
Whisk the sauce over medium heat until it comes to a gentle simmer and thickens into a glossy glaze, about 3 minutes.
Remove the baking sheet from the oven and transfer the chicken and broccoli to a large mixing bowl.
Pour the warm orange glaze over the chicken and broccoli, tossing gently to coat every piece.
Serve immediately, garnished with sesame seeds for a final touch of texture.