Peel the petai beans if not already peeled.
Slice the beans in half to check that there are no worms inside. Clean the worms and the beans.
Blanch the petai beans by steaming for 10 minutes and then dunk in ice cold water for 1 minute.
Dry the beans and diced finely.
To a bowl, add the avocado and mash with a fork.
Add the petai, chilli flakes, salt and lime juice and mix.
Spread onto 1 slice of bread before adding the second slice of bread and slicing in half.