Take a grinder, put potato, ginger, green chilli and curd. Grind all the ingredients, make a smooth paste. Take a bowl, put suji in it, add salt, sugar and mix all the grinded paste mix well add some water, make semi liquid paste. keep it for rest for 10-15 minutes. take a kadahi pour 2 cups of water and put stand on it ,c over the lid, let the water boil. greased the bowl, take suji paste put baking soda and lemon juice on it stir, pour the batter in the greased bowl. put the bowl in the stand and cover the lid, cook it for 10-12 minutes in slow medium flam. check it with tooth pick, off the gas. when it cool , demold from bowl, cut it into pieces. take a karahi put oil, add musterd seed, heeng, curry leaves, green chillies, red chili powder and turmeric powder. put dhokla pieces stir it and decorate it with coriander leaves.