First mix the rice flour in the normal room temperature water to avoid forming lumps.
Heat a kadai and add the oil. Pop the mustard seeds and urid dal. Saute the curry leaves, asafoetida powder, finely chopped green chillies, grated coconut etc.
Add the rice flour mixed with water and salt. Cook on low flame and continuously stir it.
Continue to cook till it forms a nice rice ball and leaves the edges of the kadai. In case you feel that the water is less, you can always use 1 tsp of the hot water kept aside. Do not add cold water.
Allow it to cool a little. Then knead the same well by using little oil on your palm.
Make small pidi (oval shaped dumplings) out of it and press it between your palm and fingers to get the shape as shown in the picture.
Steam it for 7-10 minutes. Your Pidi is ready.
Garnish it with some dry red chillies.
NOTES:Normally people boil the water and then mix in the rice flour. But I prefer to make it in a different way. The water requirement differs depending on the type of rice a little bit. Some rice flour absorbs more water and some don?t. Hence I suggest you keep a glass of hot water beside to add if needed.