Mash the boiled potatoes with the cheese. Add the chopped green chilies, onion slices, salt, coriander and mint leaves, black pepper and ginger. Mix well.
Make small balls out of this mashed potato mixture. Press slightly to make the balls into oval shapes (cutlets). Repeat to make 8-10 cutlets.
On a separate bowl, mix in the egg, powdered milk and flour. Beat well and set aside.
Pour the biscuit crumbs on a flat tray. Mix in a bit of oregano and kali jeera (black cumin).
Dip each cutlet in the beaten egg mixture and place it on the tray with the biscuit crumbs. Cover it well with the crumbs. Do make sure that the crumbs are not powdery, but rather crunchy. Use one hand to dip the cutlet in the egg mixture, and the other hand to cover the cutlet with the biscuit crumbs. This way the cutlet will have less of a chance to break off.
Heat a deep frying oil with just enough oil to fry 3-4 cutlets. Add one cutlet and dip another cutlet in the egg mixture and cover with biscuit crumbs. Add the cutlet to the hot oil.
Repeat this process to add 3-4 cutlets, one by one to the oil and fry until the cutlets turn brown.