In a bowl, combine all the ingredients except the oil, adding a good pinch of sea salt and 200ml of water. Mix until smooth, then leave to rest for 30 minutes.
Lightly oil a large frying pan, then place on a medium heat.
Spoon a ladleful of batter into a roti jala mould (you can buy these online) or squeezy bottle, and move in a circular motion to form a thin, lacy spiderweb pattern on the surface of the pan – keep the batter flowing. If using a mould, hold it 3cm above the hot pan and keep it full of batter for the best results.
Cook for 20 to 30 seconds, or until slightly firm but not brown, then bang out on to a board (do not attempt to flip it).
Roll up, then repeat with the remaining batter, serving as and when ready.