In a mixing bowl, whisk together flour and salt. Make a well in the middle, and gradually add in the water. While you add in the water, also stir to combine well.
Add in some chopped onions, stir well.
Grease your frying pan with adequate oil, over medium heat. Once frying pan is slightly heated, add in the batter and quickly swirl it around the pan. When the batter is slightly cooked, add in half of beaten egg. Swirl quickly to coat the batter with the egg. Sprinkle the egg surface with some chopped onions.
Continue to cook till egg is set. Flip over pancake and continue to cook the egg for a while. If you would like the pancake to be slightly browned, flip over and continue cooking for a few mins more.
Dish out and place pork floss on the pancake. Roll up the pancake (be careful, it's hot!). Slice before serving.