Mince the lemongrass very finely, using only the tender white bottom part (discard the tough outer layers and dry tops), then mince the garlic cloves. Combine the lemongrass, garlic, grated ginger, fish sauce, soy sauce, dark soy sauce, brown sugar, and white pepper in a food processor or mortar and pestle. Process until you have a smooth, fragrant paste—this creates the flavor foundation. I like using Red Boat fish sauce because it has a cleaner, more authentic flavor than other brands, which really elevates the final taste of the chicken.

Stir the oil into the marinade paste from Step 1 until fully combined. Pat the chicken thighs dry with paper towels, then add them to the marinade and toss to coat thoroughly on all sides. Cover and refrigerate for at least 3 hours, but preferably 8 to 24 hours—the longer marinating time allows the flavors to deeply penetrate the meat and tenderize it further.

Remove the marinated chicken from the refrigerator about 15 minutes before cooking to bring it closer to room temperature (this ensures even cooking). While the chicken comes to temperature, prepare your serving station: arrange lime wedges, roughly chopped fresh coriander, sliced red chili, sweet chilli sauce (Mae Ploy is my go-to brand), nam jim jaew, and coconut rice on the table. Preheat your grill or grill pan to medium-high heat (around 375-400°F if using a thermometer), lightly oiling the grates to prevent sticking.

Place the chicken thighs on the preheated grill and cook for 5 to 6 minutes on the first side without moving them—this allows caramelization and those beautiful char marks to develop. Flip the chicken and cook for another 5 to 6 minutes on the second side until the internal temperature reaches 165°F (74°C) and the meat has a rich mahogany color. I find that resisting the urge to move the chicken around helps build better flavor through the Maillard reaction, which creates that authentic grilled depth.

Transfer the grilled chicken to a clean plate and let it rest for 3 to 5 minutes—this allows the juices to redistribute throughout the meat, keeping it moist and tender. Arrange the chicken on a serving platter with the coconut rice, and scatter the fresh coriander and red chili around it. Serve immediately with lime wedges, sweet chilli sauce, and nam jim jaew on the side for drizzling and dipping.