Preheat your oven to 400°F (200°C).

Prepare the lemongrass by removing the tough outer layers and woody ends, then finely mince the tender white and light green parts.

Mince the garlic cloves and shallot finely with a sharp knife.

In a large bowl, combine the minced lemongrass, garlic, shallot, fish sauce, soy sauce, honey, sesame oil, black pepper, and red pepper flakes. Whisk until the honey is fully dissolved.

Cut the chicken thighs into bite-sized pieces (about 2 inches) and add them to the marinade. Toss with your hands to coat every piece thoroughly.

Cover the bowl and marinate in the refrigerator for at least 30 minutes, or up to 24 hours for maximum flavor development.

Heat vegetable oil in a large skillet over medium-high heat until shimmering hot.

Add the marinated chicken pieces in a single layer, working in batches if necessary to avoid overcrowding. Sear for 2-3 minutes per side until golden brown.

Transfer all the seared chicken to a 9x13 inch baking dish, including any remaining marinade from the bowl.

Bake in the preheated oven for 20-25 minutes, or until the internal temperature reaches 165°F when checked with a meat thermometer.

Serve hot over steamed jasmine rice, garnished with sliced green onions and fresh cilantro.