What do you do with a Greasy bean?

[ddsack]

I've tried 3 or 4 varieties of pole beans, and about 8 varieties of bush beans so I pretty much know what I like in green beans, but I haven't had much luck in finding out information about greasy beans. Like at what growth stage you would pick a greasy bean (or are they better as dry beans) and how you would prepare them. I would appreciate any information or ideas.