Preheat oven to 400°F and line a large baking sheet with parchment paper.
Pat the chicken breast dry and cut into 1-inch bite-sized pieces.
In a small bowl, whisk together the orange juice, orange zest, coconut aminos, rice vinegar, honey, arrowroot powder, minced garlic, and grated ginger.
Place the chicken pieces and broccoli florets on the baking sheet, drizzle with toasted sesame oil, and season with sea salt and black pepper.
Bake for 15-18 minutes until the chicken is cooked through and the broccoli is tender-crisp.
While the chicken bakes, pour the orange sauce mixture into a small saucepan over medium heat and simmer for 2-3 minutes until thickened and glossy.
Toss the baked chicken and broccoli in the thickened orange glaze until every piece is well coated.
Serve immediately garnished with sesame seeds and sliced green onions for a fresh finish.