Fluff and break up any clumps of the cold Cooked Jasmine Rice so the grains separate — day-old rice works best.
Thinly slice the Chicken (breast or thigh) and toss with a light splash of Fish sauce, a dash of Light soy sauce, a pinch of Sugar and a little White pepper; let it marinate while you prep the rest.
Crack and lightly beat the Egg. Heat a wok or large skillet over high heat with about 1–2 tbsp of Neutral oil, pour in the egg and quickly scramble until just set; transfer the scrambled egg to a plate.
Add another splash of Neutral oil to the hot pan and stir-fry chopped Garlic and sliced Onion until fragrant and the onion becomes translucent.
Increase the heat to high, add the marinated chicken and stir-fry until cooked through and lightly browned.
Push the chicken and aromatics to one side, add the Cooked Jasmine Rice to the pan and toss to combine. Stir in a tablespoon of Oyster sauce and another splash of light soy or fish sauce to taste, adjusting sweetness with a little more Sugar if needed.
Return the scrambled egg to the pan and toss everything together quickly over high heat so the rice is hot and slightly toasted; finish with a grind of White pepper and, if you like, a squeeze of Lime juice for brightness.
Stir in sliced Scallions (spring onions) and chopped Cilantro (coriander) off the heat so they stay fresh and aromatic.
Serve the khao pad immediately with wedges of Lime, sliced Tomato and Cucumber on the side, and offer chopped Thai bird's eye chilies for anyone who wants extra heat.
