Pat the chicken breast dry with a paper towel and cut into bite-sized cubes.
In a bowl, toss the chicken cubes with arrowroot powder, sea salt, and black pepper until evenly coated.
Whisk together the orange juice, coconut aminos, honey, grated ginger, and minced garlic in a small jar or bowl.
Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Add the chicken to the skillet and sear for 5-6 minutes, turning occasionally, until golden brown and cooked through.
Remove the chicken from the pan and set aside.
Add the broccoli florets to the same skillet with a tablespoon of water; cover and steam for 3 minutes until tender-crisp.
Remove the broccoli and wipe the pan clean if necessary.
Pour the orange sauce mixture into the skillet and simmer over medium heat for 2 minutes until it begins to thicken into a glaze.
Return the chicken and broccoli to the pan, tossing thoroughly to coat everything in the sticky sauce.
Steam the cauliflower rice in a separate pan or microwave until tender.
Serve the orange chicken and broccoli over the cauliflower rice, garnished with sesame seeds and sliced green onions.