Pat the chicken breast dry with a paper towel and cut into 1-inch bite-sized pieces.
In a small bowl, toss the chicken pieces with the arrowroot powder, sea salt, and black pepper until evenly coated.
In a separate glass jar or bowl, whisk together the fresh orange juice, orange zest, coconut aminos, rice vinegar, grated ginger, minced garlic, honey, toasted sesame oil, and red pepper flakes to create the glaze.
Place the broccoli florets in a steamer basket over boiling water and steam for 4-5 minutes until bright green and tender-crisp.
While the broccoli steams, heat the avocado oil in a large non-stick skillet over medium-high heat.
Add the chicken to the skillet in a single layer and sear for 3-4 minutes per side until golden brown and cooked through.
Pour the orange glaze into the skillet with the chicken, stirring constantly for 1-2 minutes as the sauce bubbles and thickens into a glossy coating.
Remove from heat and serve the orange chicken immediately alongside the steamed broccoli, garnishing with sliced green onions.