Ground the saffron and transfer it to a small bowl. Add 1 tablespoon boiling water to the saffron and let it sit until it develops color and brews.
In an stainless steel pan, pour the sugar slowly in the center.
Then slowly pour in the water, starting from the outside of the pan and going into the center so it covers the sugar. Use a wooden spoon to gently stir it just a bit.
Let it slowly heat on medium until sugar is dissolved and the mixture is bubbling.
Add in lemon juice, rose water and brewed saffron. Lower the heat and let it slowly simmer. Do not stir.
Now you can see that there are some sugar pieces sticking to the side of your pan. If they fall into the syrup, they'll cause crystals. So we dip a pastry brush in water and clean the sides of our pan. This way you dissolve the sugar granules into the mixture. Keep doing this every other minute.
After 10-15 minutes, the syrup should be ready, we're looking for a consistency like warm honey. To test, pour some on a plate (use a clean wooden spoon to take some out), refrigerate it for 2 minutes. Then rotate plate around, the syrup shouldn't move around easily.
Slowly take the pan off the heat, be careful not to move it around too much. Set aside. Take out 1 tablespoon of this syrup for the pastry dough.