Heat oil in a 4.5-litre (18-cup) slow cooker on sear (HIGH) setting; cook lamb, stirring, for 15 minutes or until well browned. Add onion, garlic, ginger and cinnamon. Cook mixture, stirring for 1 minute or until fragrant.
Add curry paste and stock; stir to combine. Cook, covered, on low for 8 hours. Season to taste.
Serve sprinkled with almonds and coriander leaves.