Wikipedia aptly describes it as the Indian Thanksgiving - and that's precisely what it is. Pongal, is a Tamilian (South India) Harvest festival. Predominantly celebrated by the farmers, India mainly being an agricultural country, this festival is way of thanking/praying Sun God for prosperous harvest for the coming year. The highlight is an earthen pot which is used to boil the milk, until it spill over which depicts prosperity - the fact that you have more than enough that it overfills....
Below are the recipes prepared during this festival 
Pongal ( Ven Pongal / Khara Pongal/ White Pongal / Spicy Pongal )
Sakkarai Pongal ( Chakkarai Pongal/ Sweet Pongal)
Kathrikai Gotsu (Eggplant/brinjal and Tamarind stew)
Rava Pongal (Savoury Semolina and lentil pudding)
Vadai (Black Gram lentil fritters)
Puran Poli (Sweet Flatbread with Lentil-Jaggery stuffing)