Wash and cook mince with 1 cup water, salt, cinnamon stick, and turmeric powder until cooked and all liquid dries up, about 20 minutes. Let cool slightly.
In a large bowl, add cooked mince and onions, ginger, garlic, green chillies, and all spice powders. Add beaten egg and gram flour and mix well. Refrigerate for at least 30 minutes so the mixture binds well later.
Peel the hard boiled eggs. Make 8 equal sized portions from the meat mixture. Take one portion of meat and flatten the meat in your palm like a cutlet. Put a hard boiled egg in the center and wrap the meat tightly around it. Tie a piece of thread around the wrapped egg. Repeat with the rest of the eggs and meat. If possible, refrigerate the eggs again. You can make the koftas till this step and refrigerate overnight.
Heat oil in a pan for deep frying. Fry the koftas. Cut the thread. To serve, slit the eggs in halves lengthwise. Sprinkle with chaat masala and serve garnished with coriander leaves and lime wedges on the side.