Meanwhile, heat the oil in a medium pan over medium heat. Add the curry paste and cook, stirring, for 1 minute or until fragrant. Add the coconut cream, kaffir lime leaves and red chilli and bring to a gentle boil.
Add the fish sauce and brown sugar, stirring to combine. Reduce heat to medium low and simmer for 15 minutes or until sauce has reduced and thickened slightly. Pour in the coconut milk and simmer for a further 5 minutes.
Stir in the green beans and bok choy. Cook for a further 1-2 minutes or until vegetables are just tender. Remove from heat.