Very simply, hard (unripened) breadfruit is starchy, like a potato, and can be used in same way that potato would be prepared. Once the breadfruit gets soft it turns sweet and is used more like a fruit. Most people, including myself, prefer breadfruit in hard starchy stage.
There is a great breadfruit book you can buy online with 101 breafruit recipes. It's an extremely versatile food...so many ways to prepare it. Like any food you have to know what you are doing. On it's own it's very bland and dull, but mixed with right ingredients it becomes fabulous. One of favorite ways here is to cook it in coconut milk and make a sort of curry out of it.
