In a bowl, mix together flour, sugar, salt and instant yeast.
Add water and make a sticky dough. It should stick to your finger when you try to pull it out of the dough. Do not add more flour. You need it to be sticky.
Fold the dough onto itself. Repeat the process for 10 times. It will become less sticky.
Apply some oil on top of the dough and set it aside for 1 hour or until double in volume.
While the dough is resting, prepare the roomal or glaze.
Mix together 1/4 cup water and flour and whisk until it dissolves completely.
Bring it to heat. Add hot water and baking soda and cook until the glaze becomes thick enough to coat the back of the spoon.
Remove from flame and allow it to cool completely.
Preheat oven to 250°C.
Line a baking tray with parchment paper and sprinkle flour on top.
Dust your hands with flour and transfer the dough to the tray.
Flatten the dough to form a rectangular disc.
With the help of your finger or the side of your palm, make horizontal indentations on the dough.
Brush the top of the dough with the roomal and sprinkle sesame seeds or nigella seeds.
Bake in hot oven for 10 minutes or until the top is golden.
Remove it and serve it hot out of oven.