Dice the chicken breast into small, even cubes and season thoroughly with sea salt and black pepper.
Heat a large non-stick skillet or wok over medium-high heat and lightly coat with a quick spray of avocado oil.
Add the chicken cubes to the hot pan and sear until golden brown and cooked through, approximately 5-6 minutes, then remove and set aside.
In the same pan, add the minced garlic, grated ginger, and the white parts of the sliced scallions, sautéing for 1 minute until highly fragrant.
Toss in the frozen peas and carrots, cooking for 2-3 minutes until they are tender-crisp and heated through.
Push the vegetables to the outer edges of the pan, crack the egg into the center, and scramble quickly until just set.
Add the chilled cooked brown rice and the prepared chicken back into the pan, stirring vigorously to combine all components.
Drizzle the coconut aminos and toasted sesame oil over the mixture, tossing for 1-2 minutes to allow the rice to develop a slight char.
Garnish the dish with the sliced green tops of the scallions and serve immediately while hot.