Place half the coriander in a large mortar. Add chili, garlic, ginger, mint, dates, lime rind, lime juice, fish sauce and sesame oil and gently pound with a pestle until a coarse paste forms. Add the remaining coriander and gently pound until well combined.
Heat a large heavy-based saucepan over high heat. Spray the base with olive oil spray. Add one quarter of the lamb and cook, turning occasionally for 3-4 minutes or until brown all over. Transfer to heatproof bowl. Repeat in 3 more batches, with the remaining lamb, reheating pan between batches.
Add the onion to the pan and cook, stirring for 1 minute or until soft. Stir in the coriander paste. Cook for 30 seconds or until aromatic. Add the lamb, coconut cream, stock, lemongrass and lime leaves. Bring to the boil. Reduce heat to low and simmer covered for 1 1/2 hours or until lamb is tender. Uncover and simmer for a further 1 hour or until sauce thickens slightly. Set aside to cool. Transfer curry to a large bowl and cover with plastic. Place in fridge overnight to chill.
Skim the fat from the surface of the curry and discard. Place the curry in a large saucepan over low heat and cook, stirring occasionally for 20 minutes or until heated through.
Divide curry among serving bowls. Sprinkle with mint and coriander and serve with rice and lime wedges.