The first step is to add chickpea flour/besan in a mixing bowl. Add chilly powder, turmeric powder, salt, cumin seeds and ajwain/carom seeds. Mix all the masala together and then add little water first. With a whisk/spoon give it a good mix so that there are no lumps formed. Then add the remaining water and make a thin batter. Add mixed herbs to it and mix. Heat oil in a nonstick pan and pour this thin batter onto the pan. Immediately begin to mix it and lower the flame. In about 2-3 minutes, this mixture will begin to thicken and not to the pan anymore. The key is to keep stirring it and cook it on low flame. Once a lump like mixture is formed take it off the flame. Let it cool down for about 5 minutes and then add boiled and grated potatoes to it. Also add salt, chopped cilantro and minced green chillies. It will be little hot but using your hands bring all of this together. Grease a cookie tray or a plate as well as your palms. Spread and flatten the mixture evenly (refer the pic above). Freeze it for 10 minutes. Meanwhile heat oil for frying. Take out the tray from the freezer, cut in squares. You can cut them in any shape you want. Fry the squares on medium flame. It should turn golden on both sides. Soak the excess oil using a paper towel. Serve them hot with chutney/ketchup.