Start by pounding coriander seeds, cumin seeds, black peppercorns, garlic, and coriander root into a paste. Mix this with fish sauce, palm sugar, salt, and water to make a balanced Thai-style marinade.
Rub the marinade over your chicken pieces, making sure every part is coated. Cover and refrigerate for at least 1 hour to let the flavors penetrate deeply.
Lightly dust the marinated chicken in tempura flour, ensuring an even coating. This creates that signature crispy crust while keeping the meat inside tender.
Heat oil in a deep fryer or heavy pot. Fry chicken in batches until golden brown and cooked through, about 8–10 minutes per batch depending on size.
Top the chicken with thinly sliced, lightly salted fried shallots. They add extra crunch and a subtle sweetness that enhances the dish.