Grind saffron threads in a mortar and pour 50 ml of boiling water over them, cover and leave to infuse for 10 minutes.
Add water with sugar, half (25ml) of saffron essence and 1 tablespoon of lemon juice in a saucepan and boil at medium heat until syrupy.
Chop pistachios finely and mix with cardamom powder.
Mix yogurt with remaining saffron essence, add eggs, 1 tbsp cold water and mix well.
Add flour and mix until your doug is smooth.
Fold in pistachio-cardamom mixture.
Melt butter in a non-stick pan over medium heat.
Add egg mixture and cover with a lid until it starts to set. Once everything has set, place a suitable flat plate on top and turn the pan with a swing. Slide the khagineh back into the pan and fry the other side for another 2 minutes.
Pour the saffron syrup on top and let it soak in with the lid open for about 5- 6 minutes until the pancake has absorbed all the syrup.
Transfer khagineh to a plate, garnish with pistachio and almond slivers and grated rose petals.
Enjoy with hot Persian tea.