Giant Polypore

Birdwatching walk at Mortonhall this morning on a beautiful crisp winter's day. Plenty of birds including nuthatches and bullfinches showing off their bright colours. Sadly none of them would pose for me :-(
A walk along the Water of Leith at Slateford rewarded me with this fungus on a felled beech tree.
My wife identified it from the photograph as a a giant polypore.