Wash and drain the rice. Shade dry the Rice for 1/2 hr. Dry roast the Urad dal to light brown. Allow it to cool.
If you are using more quantity, you can get it ground in a rice mill, else use your mixer to grind both Rice and Urad dal.
First grind rice into a fine flour, keep it aside. then grind the urad dal to fine powder. Refer this post for making Rice flour at home.
In a wide vessel, take both the flours along with salt. Mix well. Add cumin, Sesame seeds to the flour, mix well.
Whether you use Asafetida powder or the solid ones, you got to mix it in water, make sure it is dissolved before adding to the flour. If its not dissolved properly, when deep frying the murukku, there are chances for the hing to burst our due to air bubbles.
Mix in the hing to the flour and finally add the butter. Gather everything well and you will get more of a crumbling mixture. Now slowly add water and knead a dough which is little more softer than the puri dough.
Heat a kadai with oil enough to deep fry. Once the oil is hot enough, simmer to low flame.
Take the Muruku Aachu, wash and wipe it clean. Then divide the dough into equal balls. Fill the Muruku maker with the dough. You can either press it directly over the flames or press over a paper or slotted spoon and gently slide it down the hot oil. But since the quantity mentioned here is less, you can press it directly over the kadai.
Cook over medium flame, using a slotted spoon, turn it over to other side to ensure both sides turn golden colour. You will know by seeing the colour that its cooked. Remove to a kitchen paper and store it in an airtight container.
This normally stays good for weeks, provided you forget about these which hardly happens!