Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and season evenly with sea salt and black pepper.
In a small mixing bowl, whisk together the fresh orange juice, orange zest, coconut aminos, grated ginger, minced garlic, sesame oil, and arrowroot starch until the starch is fully dissolved.
Place the chicken cubes in a bowl and toss with half of the prepared orange sauce until every piece is well coated.
Arrange the coated chicken and the broccoli florets in a single layer on the prepared baking sheet.
Bake for 15-18 minutes, or until the chicken is cooked through and the broccoli is tender with slightly charred edges.
While the chicken bakes, pour the remaining orange sauce into a small saucepan and simmer over medium heat for 2-3 minutes until it thickens into a glossy glaze.
Place the cooked brown rice in a bowl, top with the baked chicken and broccoli, drizzle with the thickened glaze, and garnish with sesame seeds and sliced green onions.