Stir the sugar with hot water until melted. Add the rest of the ingredients in and let it pickles overnight if you have the time. It can be stored in the fridge for up to 1 week

Prheat a large skillet and then add in 2 Tbsp of oil. Add in the onion, garlic and leeks and stir-fry until fragrant, about 3 minutes or so. Add the ground beef and use the spatula to break up the ground beef and cook for about 2 minutes or until no longer pink. Stir in the curry powder and seasonings and cook for another minute. Have a taste and adjust seasonings to your liking. Stir fry until the filling is really dry. Remove from the heat and let it completely cool before wrapping. Stir in the beaten egg and mix. You can prepare up to this step ahead of time

Mix the flour, salt, and water in a mixing bowl. Add in the water bit by bit and then mix the dough until it comes together into a mass. It doesn't need to be smooth. Cover and let the dough rest for at least 8 hours or overnight in the fridge. The magic happens during the resting period

Bring the dough out from the fridge and let it comes to a room temperature, this may take about an hour or so. Give it a few kneads and you can see the dough has relaxed quite a bit and you can knead it few times with your hands and you will get a pretty smooth dough now

Divide the dough into 4 equal-size doughs or 6 or 8 smaller ones. Pour 2 Tbsp of oil and rub it all over the dough. Cover them a plastic wrap and rest for one hour

Oil your palm and gently pick up one dough. It is very soft and stretchy at this point

Gently flatten the dough with your palm and then use your fingers to gently pull and stretch the dough out and stretch into a roughly even square, about 10 x 10-inch in size (for large size). The dough should be quite thin and stretchy, but be careful not to stretch it too thin. If it tears a bit, don't panic, they will overlap when you wrap it.

Scoop about ¼ of the filling (for large martabak) in the middle of the dough and then fold the two sides up and followed by the top and bottom into a parcel

Preheat 3 Tbsp of oil over medium heat. Place the martabak on the pan, seam side down and cook over medium heat until golden brown and the eggs are cooked inside and then flip to the other side and cook until golden brown. Repeat the whole process until you are finished with the filling and dough. Do not crank up the heat or the outside may get burnt before the dough get a chance to be cooked through on the inside

Get one spring roll wrapper. Place ⅛ of the filling into the middle of the dough and then fold the two sides up and followed by the top and bottom into a parcel. Preheat 3 Tbsp of cooking oil in a non-stick skillet and place the martabak (seam side down) on the pan and cook until golden brown and then flip to the other side and cook until golden brown and the eggs are cooked inside

When cool enough to handle, use a sharp knife to cut the martabak into serving pieces and place them on the serving platter and serve immediately with cucumber relish on the side