Chop potatoes into even bite-sized chunks, place in a medium saucepan of boiling water
and cook for 5 minutes, or till softened, then drain.
Heat the oil in a large frying pan over medium heat and cook the onion for about a minute. Add the curry paste and saute for 2 minutes to release the aromas.
Pour in the coconut milk and water and let it come to a simmer for a further 5 minutes.
Stir in the fish sauce and sugar, then add the chicken. Turn the heat down slightly, cover and simmer for about 8 minutes or until the chicken is cooked through.
Next add the potatoes, green beans, lime zest and juice or kaffir lime and finally mix the
cornflour with 1 tbsp of the sauce from the dish, then stir. Simmer for a final 5-8 minutes til thickened slightly and heated through.
Garnish with freshly chopped coriander or basil, chilli flakes and peanuts/cashews if using. Enjoy!