Wash, peel. chop potatoes and cook them until soft. I prefer to cook in the microwave. They can also be cooked on stove-top. Let them cool completely.
Once the potaotes are cool enough, take them in a blender or indian style mixie jar, add the butter and blend them soft. Do not add water.
In a wide bowl/plate, measure the flour, add hing, cumin/sesame seeds, salt and mix it all together. Mixing is important, or else the flour mix will not be uniform
To this flour mix, add potato 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 5 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 th rest of the dough covered with a damp cloth when you are working with a batch.
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, while my oil is heating for deep-frying.
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.