Puli Vadai, also known as tamarind vadai, is a popular South Indian snack made with lentils and tamarind. It is a crispy and tangy fritter that is perfect for tea-time or as an appetizer. The lentils are soaked, ground, and mixed with tamarind pulp, spices, and herbs. The mixture is then shaped into patties and deep-fried until golden brown. The vadai is served hot with coconut chutney or sambar for a delicious and flavorful snack.