This recipe was given to me by a Burmese friend. Chayote squash is plentiful in our grocery stores, here in the U.S. In Australia it's called Choko squash, in India it has many names such as Bangalore and Darjeeling Squash. In Darjeeling it's called Iskoos. It is a very versatile vegetable that has little flavour of its own and absorbs the flavour of other ingredients in the dish. I use it as a substitute for bottle gourd (calabash) in Indian recipes, because it is more readily available. You could also replace the chayote squash with and equal number of large zucchini.