Preferred Vathals: Sundakai (turkey berry), Manathakkali (black night shade), mango
Preferred vegetables: shallots, eggplant, red pumpkin, drumstick, onions
You have neither: take one whole urad papad (plain), break into pieces, fry in the initial tempering oil, and proceed as usual. This is not very commonly done, but it's amazing!
Serve with hot rice, with a drizzle of oil or ghee and a side of papad.
Also great with cool yogurt rice on a warm summer evening.