Pat the chicken breast cubes dry with a paper towel and season evenly with sea salt and black pepper.
In a small mixing bowl, whisk together the orange juice, orange zest, coconut aminos, rice vinegar, honey, arrowroot powder, grated ginger, and minced garlic until smooth.
Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Add the chicken to the skillet in a single layer and sear until golden-brown and cooked through, approximately 6 to 8 minutes.
Remove the chicken from the skillet and set aside on a plate.
Add the broccoli florets to the same skillet with a tablespoon of water; cover with a lid and steam for 3 minutes until tender-crisp.
Remove the lid and pour the orange sauce mixture over the broccoli, stirring constantly as it bubbles and thickens into a glossy glaze.
Return the cooked chicken to the skillet, tossing thoroughly to coat every piece in the zesty orange sauce.
Transfer to a plate and garnish with sesame seeds and sliced green onions before serving warm.