Pat the chicken breast dry and cut into bite-sized pieces, then season evenly with sea salt and black pepper.
In a small glass bowl, whisk together the fresh orange juice, coconut aminos, honey, arrowroot powder, minced ginger, and minced garlic until the starch is fully dissolved.
Heat the avocado oil in a large stainless steel or cast iron skillet over medium-high heat until the oil is shimmering.
Add the chicken pieces to the skillet in a single layer and sear without moving for 3 minutes to develop a golden crust, then flip and cook for another 2-3 minutes until finished.
Remove the chicken from the pan and set aside; immediately add the broccoli florets and a splash of water to the hot skillet.
Cover the skillet with a lid for 2 minutes to steam the broccoli until it is vibrant green and crisp-tender.
Return the chicken to the pan and pour the orange sauce mixture over the ingredients, stirring constantly for 1 minute as the sauce bubbles and thickens into a glossy glaze.
Transfer to a plate and garnish with thinly sliced green onions and sesame seeds before serving.