Wash and soak urad dal for 30 minutes. Pressure cook until soft by adding water 1 inch above the dal.
Let the pressure fall on its own. Take the dal in a mixer/blender, add butter to this and bend it smooth, do not add any water. The consistency should be of vada batter.
In a wide bowl/plate take rice flour, sprinkle cumin seeds, sesame seeds, hing and salt. Mix well, to get a uniform flour mix, It is important to mix well to get a homogeneous flour.
To this flour mix, add urad dal puree in 2 batches and make a soft dough. I added ½ cup water to the mixer jar and used that water too to make the dough. You might not need the full ½ cup, use little by little towards the end to make a soft dough.
Once the dough is ready, divide it into 7-8 portions. Keep the muruku press ready with thenkuzhal achu/mould, a plate with 3 holes in triangle shape. Put a portion of the dough into the press and keep it ready. Keep the rest of the dough covered with a damp cloth when you are working with a batch.
Heat oil for deep-frying. While the oil is heating, spread a newspaper on the kitchen counter or your worktop, press the murukku onto the paper. I make around 10-15 murukku ready on the paper.
Drop a pinch of dough into the hot oil, when it sizzles back up to top, then the oil is ready for frying. Transfer 4-5 murukkus from the paper to the hot oil, using a flat spatula.
When you add the murukku to the hot oil, the oil will bubble up, let that sieze, then use a slotted spoon and turn the murukku inthe hot oil. Cook on the both sides until the murukku turn golden brown in color
Remove the murukku from the oil using a slotted spoon and drain it on a kitchen towel. When it cools down, store it in an air-tight container and enjoy your snack.