Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into bite-sized cubes and season them evenly with sea salt and black pepper.
In a small mixing bowl, whisk together the fresh orange juice, tamari, honey, sesame oil, grated ginger, minced garlic, and arrowroot powder until the mixture is smooth.
Spread the chicken cubes, broccoli florets, and sliced red bell peppers across the prepared baking sheet in a single layer.
Drizzle the orange glaze over the chicken and vegetables, tossing with tongs to ensure every piece is thoroughly coated.
Bake for 15 to 18 minutes, or until the chicken is cooked through and the sauce has thickened into a glossy, sticky glaze.
Divide the cooked brown rice into bowls and top with the baked orange chicken and vegetable mixture.
Finish the dish by garnishing with sesame seeds and freshly sliced green onions before serving warm.