Wash the rice and soak in three cups of fresh water for at least two three hours. Wash and soak the dal in two cups of water for a similar time. Drain and grind the rice to a slightly coarse texture. Use water as required to make a batter of dropping consistency.
Drain and grind the dal, sprinkling water as required to a smooth and spongy batter. Mix both the batters. Sprinkle salt and mix thoroughly in a whipping motion using your hand. Pour batter into a large vessel, close tightly with a lid and rest in a warm place overnight. Heat sufficient water in a steamer. Place a wet muslin cloth on the mini idli stand. Pour a spoonful of the fermented batter into each dent.
Place the idli stand in the steamer. Cook for eight to ten minutes or till idlis are done. Demould the idlis when slightly cooled. Skewer the idlis and vegetables onto each toothpick in the following order: onion, idli, capsicum, idli, tomato. Heat the oil in a pan and arrange the toothpicks on it. Add the tomato ketchup and red chilli sauce and toss. You can serve them with rasam. Pour a little rasam into small glasses, place the toothpicks across the rims and serve immediately.