Preheat oven to 400°F and line a large baking sheet with parchment paper.
Cut the chicken breast into 1-inch cubes and place them in a large bowl with the broccoli florets.
In a small saucepan, whisk together the orange juice, orange zest, coconut aminos, rice vinegar, honey, sesame oil, arrowroot powder, minced garlic, and grated ginger.
Place the saucepan over medium heat and stir constantly for 2-3 minutes until the sauce thickens into a glossy glaze.
Pour the orange glaze over the chicken and broccoli, tossing thoroughly until every piece is well-coated.
Arrange the mixture in a single layer on the baking sheet and sprinkle with red pepper flakes, sea salt, and black pepper.
Bake for 15-18 minutes until the chicken is cooked through and the sauce is bubbly and caramelized.
Garnish with thinly sliced green onions and serve immediately.