Until yesterday I had a dual boot debian / win8 with grub that worked like a charm. Yesterday a stupid windows update totally wiped grub and I'm now unable to boot in linux.I installed linux a year ago and I remember it was quite a pain to properly make grub work and I don't even remember all the steps involved.What is the correct procedure to restore it? 
How do I restore grub on a uefi boot after a windows update wiped it?
debian;windows;grub2;uefi