Take 40ml of the lukewarm water, mix with instant yeast and leave for 5 mins.
Combine the dry dough ingredients together with a fork, except the potato, then add the yeast mix, the rest of the water and the yoghurt. The mix should be wet and sticky and have the texture of a paste. Cover with a wet towel and allow it to rise for 1-2 hrs. Boil the whole potato, with skin on, for 25-30 mins, peel then return to a dry pan on low heat to take out excess moisture. Blend to form a smooth mash.
Prepare the sugar glaze by heating the sugar with water, cardamom and saffron for 15 mins, take off the heat add a squeeze of lemon and allow to cool completely.
When the dough has risen, add the mashed potato and mix with a fork very well.
Heat some vegetable oil, in a deep frying pan, to medium-high heat, and then lower the heat. Grease your hand and teaspoon with some oil, take a handful of the wet dough, make a fist with your hand and squeeze, so that a small dough ball comes out from the area between your thumb and index finger. Scrape it off with the oiled teaspoon, drop it in the oil and fry on gentle heat until they turn golden – this should take 5-7 mins. Remove the fried balls with a slotted spoon, place on a kitchen paper to absorb excess oil, pour the sugar glaze over, and serve.