Boil the potatoes. You could use a pressure cooker, instant pot or boil them in a pan on the stove.
Once they have boiled well, remove from the water immediately. Peel them and keep them aside to cool.
Once cool, mash them evenly using a potato masher or else grate them into a mixing bowl.
To the potatoes now add all the dry spices, ginger, chillies, coriander leaves, cornstarch, lime juice and mix everything very well. Make sure there are no lumps.
Oil your palms very slightly and divide this potato mixture into equal portions.
Take one portion, shape into a sphere, flatten it on one palm and place a cashew and raisin, or you may choose to add either one of the two. Bring the side together so as to make a sphere again and gently flatten into a tikki/ patty shape. Follow the same procedure for the other tikkis too and keep them aside.
Heat a pan and add 2-4 tbsp oil. A cast iron pan works very well here and give a very good golden brown sear to the tikkis. Pan fry the tikkis for 2-4 minutes on each side until you get a beautiful golden brown on both side. Traditionally, these tikkis are deep fried. That is completely your choice.
Fry all the tikkis in a similar way; add more oil whenever needed. Remove the tikkis on a paper towel.
Serve hot immediatelt with chutneys and/ or a sauce of your choice.