Pat the chicken breast dry with paper towels and toss in a medium bowl with arrowroot powder, sea salt, and black pepper until coated.
Heat the avocado oil in a large skillet or wok over medium-high heat until shimmering.
Add the chicken to the skillet and sear until the exterior is golden-brown and crispy, then remove and set aside.
In the same skillet, add the sesame oil, minced garlic, and grated ginger, stirring for 30 seconds until fragrant.
Add the diced carrots and peas to the pan, sautéing for 2-3 minutes until the carrots begin to soften.
Stir in the cooked brown rice and tamari, pressing the rice down to ensure it gets slightly toasted in the pan.
Return the crispy chicken to the skillet and toss everything together to combine and heat through.
Garnish the dish with sliced green onions and sesame seeds before serving.