My Taiwanese neighbor handed me a fruit/vegetable from his tree (because he said I have the same tree in my yard). It is green and looks like an artichoke with all its leaves fused together. The rind is a hard goard-like rind. I thought he said is was "shitimoya" (sp), but I can't find anything like it on-line. I live in Southern California, and this neighboring gardener grows a variety of tropical and/or asian plants, mostly fruits and vegetables.
To make it taste like expensive vanilla ice-cream, quarter it and pop it in the freezer for 30-45 minutes first.
