When I was at a rice field in Thailand, I saw these beautiful ivy gourds hanging from a fence. Before I was done taking pictures, my mother's hand had reached to pick them. We came home that day and made tindora curry. So, when I was at my local Indian store and saw tindora, I jumped at the chance of making the curry.
Tindora or Ivy Gourd is not a common ingredient that you would find at a market in Thailand. The ivy gourd leaves are more a common and available at any market in bundles. Most Thai people probably don't know that the green fruit is edible. The only way to get to enjoy this wonderful curry is to forage for tindora and make the curry yourself.
Fortunately if you live in the US near an Indian/Pakistani market, you will see fresh tindora/ivy gourds from time to time. The fruit that's available here in the US is the non-bitter ones where in Thailand they are notoriously bitter.
Tindora gives the curry a slight crunch that you normally don't find in a vegetable that's cooked in a curry sauce. The curry is thickened with crab meat and lacks most of the soupy liquid many other curries have.