Dice chicken into small bite-sized pieces and toss in a bowl with arrowroot powder, garlic powder, ginger powder, salt, and pepper until evenly coated.
Heat a large non-stick skillet or wok over medium-high heat and add half of the sesame oil.
Add the chicken to the pan and sear until golden brown and crispy on all sides, about 5-6 minutes, then remove from the pan and set aside.
In the same pan, add the remaining sesame oil along with the diced carrots and peas, sautéing for 3 minutes until tender-crisp.
Push the vegetables to the side, crack the egg into the pan, and scramble until just set.
Add the cooked brown rice and crispy chicken back into the pan, drizzling with tamari and tossing everything together for 2 minutes to heat through.
Garnish with sliced green onions and serve immediately while the chicken is still crunchy.