Curd rice, native to South India, is rice flavored with yogurt and seasoned with a variety of lentils. Sometimes, milk is also added to the rice to reduce the sourness of the curd. This is not something we usually make at home. I have a faint (sweet!) memory of eating thayir sadam when I was young while visiting a relative in (then) Madras.
Recipe courtesy: Deepa's Simple Home Cooking