Heat oil in a wok and add curry paste. Fry gently until bubbling and fragrant.

Add prawns, kaffir lime leaves and lemon grass. Fry for 2 minutes until the prawns are pink.

Stir in the coconut milk and bring to a gentle boil. Simmer, stirring occasionally, for 5 minutes or until the prawns are tender.

Stir in the fish sauce, cucumber and whole basil leaves. Top with green chillies and serve.