Idli Rice also Romanized idly or idly is a traditional breakfast in south Indian households. Idli is savory cake of South India that is most popular throughout the southern part of India including Karnataka, Tamil Nadu, Pondicherry, Kerala, Andhra Pradesh and neighboring countries. The cakes are usually two to three inches in diameter and are made by steaming a batter consisting of fermented black lentils (de-husked) and rice.