St. Martin’s Day for us is Veterans’ Day, aka Armistice Day. In Germany, France, and much of Europe it is both Armistice or Remembrance Day, and a day for having bonfires, marching in night processions carrying lanterns, wearing costumes, and… eating a nice fat goose!
This is particularly a thing in Germany, where the Martinsgans dinner is as popular as our Thanksgiving turkey. (And yes, PETA has a stupid German website about it.) You would also want to eat red cabbage, apples, things with caraway, etc….
This article talks about regional differences with stuffing flavors, among other things.
Here is a recipe in English telling you how to cook your goose. (In a culinary way.)