Toast the white peppercorns in a dry skillet over medium heat for 1-2 minutes until fragrant, then grind them into a fine powder using a mortar and pestle or spice grinder. Using the same mortar and pestle, crush the minced garlic, cilantro stems, and sugar together into a coarse paste. In a bowl, combine the paste with fish sauce, soy sauce, and water to create the marinade. Cut the chicken into 2-inch pieces and make shallow 1 cm slits into the thicker parts to help the marinade penetrate evenly. Add the chicken to the marinade, ensuring all pieces are submerged, then cover and refrigerate for at least 4 hours or overnight for deeper flavor development.

Thinly slice the shallots into 1/8-inch rings and toss with salt in a small bowl. Let them sit for 10 minutes to draw out excess moisture, which prevents splattering during frying. Gently pat the shallots dry with paper towels. Pour the frying oil into a heavy-bottomed pot or wok and heat to 250°F on medium-low heat. Add the dried shallots and fry slowly for 5-8 minutes, stirring occasionally, until they turn golden and crispy. The low temperature ensures they brown gently without burning. Using a slotted spoon, transfer the crispy shallots to a paper towel-lined plate and set aside.

In a shallow bowl, combine the rice flour and baking soda—the baking soda creates a light, airy coating that fries up extra crispy. I always use Erawan brand rice flour because it yields that signature crunch. Remove the marinated chicken from the refrigerator and, working in batches, coat each piece thoroughly in the flour mixture, shaking off excess. Increase the oil temperature to 375°F over medium-high heat. Once the oil reaches temperature, carefully add the coated chicken pieces in batches—avoid overcrowding, which lowers oil temperature and creates greasy results. Immediately reduce heat to 300°F and fry for 6-8 minutes for smaller pieces like wings or 10-12 minutes for thicker thighs, stirring occasionally for even cooking.

Transfer the fried chicken to a clean paper towel-lined plate and let it rest for 5-10 minutes—this brief resting period allows the coating to set and the residual heat to cook the chicken through while it cools. The chicken will continue to crisp up as it cools. Arrange the chicken on a serving platter and top with the crispy shallots from Step 2. Serve immediately alongside warm sticky rice, Thai sweet chili sauce for dipping, and fresh cilantro sprigs as garnish.