In a small bowl, whisk together the tamari, rice vinegar, honey, grated ginger, minced garlic, red pepper flakes, arrowroot powder, and water until the starch is fully dissolved.
Cut the chicken breast into uniform bite-sized pieces and season them evenly with sea salt and black pepper.
Heat the sesame oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet and sear for 5 to 6 minutes, stirring occasionally, until the pieces are golden brown and cooked through.
Add the broccoli florets and a splash of water to the pan, then immediately cover with a tight-fitting lid to steam for 2 minutes until bright green and crisp-tender.
Remove the lid and pour the prepared sauce over the chicken and broccoli, stirring constantly for about 1 minute until the glaze thickens and becomes glossy.
Serve the glazed chicken and broccoli immediately over a bed of warm, nutty brown rice for a complete and balanced meal.