Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Cut the chicken breast into one-inch cubes and season evenly with sea salt and black pepper.
In a small mixing bowl, whisk together the orange juice, tamari, honey, sesame oil, cornstarch, grated ginger, and minced garlic.
Place the chicken cubes and broccoli florets on the prepared baking sheet and drizzle with half of the orange sauce mixture.
Toss to coat the chicken and vegetables thoroughly, then spread them out in a single layer.
Bake for 15 to 18 minutes until the chicken is cooked through and the broccoli edges are slightly charred.
While the chicken bakes, pour the remaining sauce into a small saucepan and simmer over medium heat for 2 minutes until thickened into a glaze.
Remove the tray from the oven, drizzle the thickened glaze over the chicken and broccoli, and serve over the cooked brown rice.