Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and chop the broccoli into small, uniform florets.
Place the chicken and broccoli on the baking sheet, drizzle with olive oil, and season with sea salt and black pepper.
Toss the ingredients well to coat, spread them into a single layer, and bake for 15-18 minutes until the chicken is cooked through.
While roasting, combine the orange juice, tamari, rice vinegar, honey, minced ginger, minced garlic, and arrowroot starch in a small saucepan.
Place the saucepan over medium heat and whisk constantly for 3-5 minutes until the sauce thickens into a glossy, translucent glaze.
Remove the baking sheet from the oven and transfer the chicken and broccoli into a large mixing bowl.
Pour the warm orange glaze over the chicken and broccoli, tossing gently until every piece is thoroughly coated before serving.