Pat the chicken breast dry with paper towels and toss in a bowl with arrowroot powder, sea salt, and black pepper until evenly coated.
Heat the avocado oil in a large skillet or wok 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, then remove and set aside.
In the same skillet, add the broccoli florets and two tablespoons of water; cover with a lid to steam for 2 minutes until tender-crisp.
Remove the lid and stir in the minced garlic and grated ginger, sautéing for 1 minute until the aromatics are fragrant.
In a small jar, whisk together the coconut aminos, rice vinegar, honey, and red pepper flakes to create the sauce.
Return the cooked chicken to the skillet, pour the sauce over the mixture, and toss constantly for 1 to 2 minutes until the glaze is thick and glossy.
Remove from heat, drizzle with toasted sesame oil, and garnish with sliced green onions before serving.