Combine coriander, cumin, turmeric, pepper, chilli, garlic, ginger and lemon juice in a bowl to form a paste. Set aside.
Heat 1 tablespoon of oil in a large saucepan over high heat. Add half the beef. Cook, stirring, for 2 to 3 minutes, or until browned. Transfer to a bowl. Repeat with remaining oil and beef.
Reduce heat to medium. Add spice paste. Cook for 1 minute. Return beef to saucepan. Cook, stirring, for 1 minute, or until meat is coated with paste. Add tomato paste and stock. Bring to the boil. Reduce heat to low. Cover. Cook for 1 hour 45 minutes, or until beef is tender.
Remove lid. Cook, uncovered, for a further 15 minutes, or until sauce has reduced and thickened slightly. Serve with rice and raita. Top with mint , coriander and fresh chilli (optional).