I think you might have meant Hen of the Woods as Chicken of the Woods is a bright orange colored mushroom. Not sure but your picture looks like a Umbellate Polypore. They can grow quite large and in groups. Supposely they good to eat when young, but I never tried them. I'll only eat a mushroom if I am 100% of it's identification. Let me dig out some of my shroom books to see if I can come up with more information.
I agree with the polypore id. Not the best eating. They tend to be a little tough. One thing you can do is to dry it and grind it into a powder and use it to season soups, etc. Personally, I don't think they are worth the bother.