Rice, lentils, coconut and tamarind: fermented batters, sour broths and a sizzle of mustard seed and curry leaves, from the tiffin that starts the day to the feast on a banana leaf.
The south grows rice, not wheat, and much of its cooking starts with rice and lentils soaked, ground wet and left to ferment overnight — the batter for idli and dosa. Tamarind brings sourness, coconut brings richness, and nearly everything is finished with a tempering of mustard seed, curry leaves and dried chilli in hot oil.
It's many kitchens, not one. Tamil Brahmin and Udupi temple cooking is vegetarian; in Kerala, Hindu, Syrian Christian and Mappila Muslim families each cook fish, meat and coconut their own way; and the Chettiar merchants of Chettinad are known for fiercely spiced meat. The Malabar coast sold pepper, cardamom and ginger to Arab, Chinese and later European traders for centuries, and the Portuguese, Dutch and British all came for it.
Hyderabad, up on the Deccan, is another story again: its Nizams kept a court kitchen in the Mughlai and Persian tradition, and its biryani is now the city's pride. In the twentieth century, restaurants run by cooks from Udupi carried dosa and sambar across India and beyond.