If we are going to delve into South Indian food, I suppose the Dosai would be a beffiting point of entry. The Dosai is simply a sort of pancake made with a fermented batter of lentils (Urad Dal a.k.a black gram) and rice (generally raw rice). The lentils and rice are left to soak for 5 to 6 hours, then ground to a paste.
Deva's Kitchen 