In a small bowl, whisk together the fresh orange juice, orange zest, coconut aminos, arrowroot powder, minced ginger, and minced garlic until the arrowroot is fully dissolved.
Pat the chicken breast dry with paper towels and cut into bite-sized 1-inch cubes, then season evenly with the sea salt and black pepper.
Heat the avocado oil in a large skillet or wok over medium-high heat until it begins to shimmer.
Add the chicken cubes to the skillet in a single layer and cook for 6-8 minutes, turning occasionally, until they are golden brown and cooked through.
Add the broccoli florets to the pan along with two tablespoons of water; immediately cover with a lid and steam for 2-3 minutes until the broccoli is bright green and crisp-tender.
Remove the lid and pour the prepared orange sauce mixture over the chicken and broccoli.
Stir constantly for 1-2 minutes over medium heat until the sauce bubbles and thickens into a glossy, translucent glaze that coats the ingredients.
Garnish the dish with sesame seeds and serve immediately while the glaze is hot and sticky.