Lower the flame. remove the extra oil and and keep 2 tbsp oil in the same pan. let the oil temperature come down. in the same oil, add asafoetida powder. stir well.
then add the red chilli + water solution and stir well. be careful as the mixture splutters.
now add the beaten curd. when you are adding the curd, with a spoon or wired whisk, stir continuously, so that the curd does not split. add the curd on a low flame.

After adding curd, add water and continue to stir.
stir and mix very well.
then add fennel powder. if you do not have ready fennel powder than you have to make it. roast the fennel lightly on a pan or tava. when cooled, then in a mortar & pestle pound the roasted fennel seed to a medium fine powder. you can also grind in a small spice grinder or coffee grinder.
add the whole spices and ginger powder. stir well.
now add the potatoes. again stir.
season with salt and stir again.