Thirunelveli Halwa, also known as Tirunelveli Halwa or Iruttu Kadai Halwa, is a famous and traditional South Indian sweet delicacy. It hails from the town of Tirunelveli in the southern state of Tamil Nadu, India. 

Thirunelveli Halwa is a unique and delectable sweet made primarily from wheat, sugar, ghee (clarified butter), and sometimes cardamom for flavour. It has a distinctive texture that is both soft and slightly chewy. The color of the halwa can range from deep brown to a rich golden hue, depending on the preparation method and the quality of ingredients used.