Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Rinse the jasmine rice under cold water until clear, then cook according to package instructions until light and fluffy.
Cut the chicken breast into uniform 1-inch pieces and toss them in a bowl with the sea salt and black pepper.
In a small saucepan over medium heat, whisk together the orange juice, tamari, rice vinegar, honey, minced garlic, grated ginger, and arrowroot powder.
Bring the sauce to a gentle simmer for 3 to 5 minutes, stirring constantly until it thickens into a glossy, translucent glaze.
Spread the chicken pieces and broccoli florets across the prepared baking sheet and drizzle with half of the prepared orange glaze.
Bake for 15 to 18 minutes, or until the chicken is cooked through and the broccoli edges are slightly caramelized.
Remove from the oven and toss the chicken and broccoli with the remaining glaze to ensure every piece is well coated.
Serve the orange chicken and broccoli over the cooked jasmine rice, garnishing with toasted sesame seeds and thinly sliced green onions.