Dry roast the moong dal and chana dal separately until nice aroma comes. Cool and grind to a fine powder.
In a large bowl, sieve rice flour and moong and chana dal powder. Add cumin seeds, sesame seeds, asafoetida, salt, butter and hot oil.
Mix well with hands till butter is incorporated well. Add water little by little and make a smooth and soft dough.
Divide the dough into 4 equal portions and cover with a wet cloth to prevent drying.
Heat oil for deep frying. Take the murukku press and insert the star disc. Fill the murukku press with one portion of the dough.
Grease two (or three) ladles. Squeeze murukku in circles on the greased ladles. You can also directly squeeze into hot oil.
Gently slide into the oil and cook in medium heat. Fry both sides till murukku turns golden brown and the bubbles cease. Drain on a paper towel.