Pat the chicken breast dry and dice into small, bite-sized pieces.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat until shimmering.
Add the diced chicken to the pan and season with sea salt, black pepper, garlic powder, and ginger powder.
Sauté the chicken for 5-6 minutes until golden brown and cooked through, then push it to the outer edges of the pan.
Crack the egg into the center of the pan and scramble quickly with a spatula until just set.
Add the diced carrots and frozen peas to the pan, stirring with the chicken and egg for 2 minutes until the vegetables are tender-crisp.
Fold in the chilled cooked jasmine rice and pour the tamari over the top.
Toss everything together continuously for 3 minutes, allowing the rice to heat through and absorb the flavors.
Remove from heat, garnish with thinly sliced green onions, and serve warm.