Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
In a small mixing bowl, whisk together the fresh orange juice, coconut aminos, rice vinegar, honey, minced ginger, minced garlic, and arrowroot powder until the starch is fully dissolved.
Place the cubed chicken breast and broccoli florets into a large bowl, then toss with sesame oil, sea salt, and black pepper until evenly coated.
Spread the chicken and broccoli in a single layer across the prepared baking sheet.
Pour the orange sauce mixture over the ingredients on the sheet, tossing gently with a spatula to ensure every piece is well-coated.
Bake for 18-20 minutes, or until the chicken is cooked through and the sauce has reduced into a sticky, glossy glaze.
Remove from the oven and garnish with sesame seeds before serving.