First wash and soak the rice in sufficient water for about 3 hrs. Drain the water from the rice.
Spread the rice on a clean cloth and leave it to rest at room temperature. The excess water from the rice should dry off, but the rice should still be moist to touch. Transfer the rice to a mixie / blender and grind to a fine powder. Sieve the rice flour. Grind the coarse rice which was filtered out and repeat the process of sieving. Keep it aside.
Now, Dry roast the urad dal until golden brown. Turn off the flame and leave it to cool down to room temperature. Grind the urad dal to a fine powder and sieve it similar to the rice.
Measure the finely powdered rice and urad dal and add it to a large mixing bowl. Add the remaining ingredients (butter, salt, asafoetida, jeera and hot oil) and mix well until combined.Sprinkle sufficient water and knead it into a smooth dough.
Place a plastic bottle cap in the center of a parchment paper. Grease your hand with oil and take a small portion of the dough. Roll it out using your fingers and stick it to the cap. Then gently using a twist and turn motion, roll out the dough into the shape of murukku.
Meanwhile heat oil in a kadai for frying. Once the oil is hot turn the flame to medium. Slide the murukku dough into the oil and fry until nicely golden.
Store it in an airtight container and enjoy.