I was looking for a curry recipe to use up some of the lovely yellow squash & zucchini we have growing and came across this style of curry on a blog called yummyoyummy. According to the original author, it's a Kerali style dish, and it is certainly very easy to prepare. I changed the cooking process slightly, and added in the leek which is much better than onion in this dish. If you can use yellow squash/zukes here, the end colour will be a beautiful light chartreuse. Servings are a bit of a guess, I think you would serve this alongside a few other things, would be enough for 4 in that case.