Place rice flour in a bowl and add some freshly ground salt and pepper. Place egg and coconut in separate bowls. Holding the prawns by the tail, dip them one by one into the flour and shake off excess. Dip prawns into the egg and then press firmly into the coconut to evenly coat. Transfer to a plate.
Add enough oil in the frypan to reach a depth of around 6cm. Heat to 170oC on medium-high heat (when the oil is ready, a cube of bread will turn golden in 20 seconds). Add the prawns to the oil in batches and cook for 1 - 2 minutes or until golden brown. Use a slotted spoon to transfer to a plate lined with paper towel. Repeat with remaining uncooked prawns.
Serve prawns with a dipping sauce.