Preheat oven to 400°F and line a large baking sheet with parchment paper.
In a small bowl, whisk together the fresh orange juice, orange zest, tamari, rice vinegar, honey, sesame oil, arrowroot powder, minced ginger, and minced garlic to create the glaze.
Place the cubed chicken breast and broccoli florets onto the prepared baking sheet in a single layer.
Season the chicken and broccoli evenly with sea salt, black pepper, and red pepper flakes.
Pour half of the orange glaze over the chicken and broccoli, tossing thoroughly to ensure every piece is well coated.
Bake for 15 to 18 minutes, or until the chicken is cooked through and the broccoli is tender with slightly crispy edges.
Remove from the oven and drizzle the remaining glaze over the hot chicken and broccoli before serving immediately.