Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into one-inch cubes and place them in a bowl with the broccoli florets, avocado oil, sea salt, and black pepper.
Toss the chicken and broccoli until evenly coated, then spread them in a single layer on the prepared baking sheet.
Roast in the oven for 15 to 18 minutes, or until the chicken is cooked through and the broccoli is tender-crisp.
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 for 2 to 3 minutes until it simmers and thickens into a glossy glaze.
Remove the roasted chicken and broccoli from the oven and transfer them to a large mixing bowl.
Pour the warm orange glaze over the chicken and broccoli, tossing gently to coat every piece.
Garnish with sesame seeds and serve immediately for a fresh, clean-eating dinner.