Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into uniform 1-inch cubes and season evenly with sea salt and black pepper.
Spread the chicken in a single layer on the prepared baking sheet and bake for 15-18 minutes until fully cooked and lightly golden.
While the chicken is roasting, combine the orange juice, tamari, honey, rice vinegar, sesame oil, grated ginger, minced garlic, and cornstarch in a small saucepan.
Whisk the sauce over medium heat until it comes to a gentle simmer and thickens into a glossy, translucent glaze.
Steam the broccoli florets in a steamer basket or microwave with a splash of water until they reach a vibrant green and tender-crisp texture.
Remove the chicken from the oven and transfer to a bowl, tossing thoroughly with the warm orange glaze.
Serve the glazed chicken over the cooked brown rice with the steamed broccoli on the side, finishing with a sprinkle of sesame seeds.