Crayfish in Garlic and Walnut Sauce

I came across this delicious dish completely by chance.

We visited the Green Coast Restaurant, on the lake of Ioannina in northwestern Greece, looking for a suitable spot to photograph the Smoked Trout in Dill and Scallion Marinade.

We found our spot, and as we were preparing our shots, Mrs. Parthena Koloka, the owner, offered to cook us this specialty of hers. I had never heard of a dish like the one she described, but I q