Trim any fat from the pork, cut the meat into thin strips and place them in a bowl with the coriander. Add the chilli, garlic and lime juice, toss well to coat the meat evenly, then cover and leave it to marinate for 30 minutes.
Heat the oil in a heavy-based frying pan and fry the onions over a medium-high heat for 3-4 minutes until they just begin to brown, stirring frequently. Add the marinated pork and continue cooking for a further 10 minutes, or until the meat is browned, stirring frequently.
Add the rajmah and tomatoes to the pan, season well and simmer for 3-4 minutes until the tomatoes have softened.
Heat the grill to high, then warm the chapati through for about 1 minute, turning once.
Divide the pork mixture between the chapati. Top each one with curd and mint and fold the chapati over. Serve them with lime wedges.