Soak the basmati rice and parboiled rice in a large bowl of water for 1 hour. At the same time, soak the lentils in another large bowl of water for 1 hour.
Drain the rice, transfer to a blender or food processor and add the red chilies and asafoetida.
Process, gradually adding 3 tablespoons of water to make a coarse batter. Transfer to a clean bowl.
Drain the lentils, transfer to a blender or food processor and process, gradually adding 2 tablespoons water to make a coarse batter.
Combine the rice and lentil batters and mix in the coconut, fenugreek leaves, and season with salt. Stir in a little water, if necessary, to make a thick batter of pouring consistency.
Heat a tawa, flat griddle or frying pan (skillet) over high heat until it sizzles when a few drops of water are sprinkled on to it.
Pour a ladleful of the batter into the centre of the tawa and spread it out quickly using a circular motion with the back of the ladle to form a 15cm / 6 inch round adai. Make a hole in the centre and drizzle 1 teaspoon oil around the edges and centre.
Reduce the heat and smear a very thin film of oil evenly over the tawa. Cook for about 2 minutes, or until the base is golden. Turn carefully with a spatula and fry the other side for a further 2 minutes, or until crisp and golden.
Transferto a serving plate and serve hot. Make the others inthe same way.