Place the lamb, onion, garlic and ginger in a non-stick skillet and cook over medium heat until the lamb is cooked through. Add the curry powder and stock or beer and cook 2 to 3 minutes, or until the stock or beer has almost evaporated; stir in the cilantro and season with salt. Cool the mixture to room temperature, and then mix in the egg. Lay three roti flat on a work surface. Divide and spread an equal amount of the lamb mixture on each roti. Top with the other three roti. In a lightly oiled, nonstick pan, set over medium heat, cook the roti for 2 to 3 minutes or until the lamb is heated through and the egg is cooked. Cool for a minute and then cut each stuffed roti into 8 wedges; arrange on platter and serve with mango chutney for spooning on top.
Note: Roti, an Indian-style flat bread, is available in the deli department.