Combine flour, salt, sugar, and instant yeast. Whisk to combine. Add water and whisk until combined. Add beaten egg and whisk again until combined. Rest the batter for one hour
While waiting for the batter, you can prepare the filling of your choice
Cook and fill the pancake:
Preheat non-stick pan over medium-low heat. Don't use any oil. After one hour, you will see lots of bubbles. Give the batter a good stir. Ladle about 60 ml of the batter onto the pan. Bubbles will start to appear. Cook until the top is no longer wet
Remove from the pan and immediately scoop about one tablespoon of filling and fold the pancake over and pinch the edges to seal. Use a fork to crimp the edge to make it look like empanada. If you have the empanada mold, you can use that
It is important to fill the pancake right away after cooking so it will "seal". If you wait until the pancakes are cold to fill, they won't seal properly. I suppose this is the tedious part about making apam perlis/martabak lenggang. It's great if you have someone to have you fill the pancake. Even if you don't have, it's still pretty manageable