Grind walnuts in blender, then combine with the rest of the burger mixture ingredients.
Let the mixture rest in the refrigerator for about an hour to let the flavors meld together.
Form the mixture into patties. The entire mixture will make 8-12 burgers depending on the size of the patty formed. It is recommended to use half of the mixture now and reserve the rest for use in another recipe or for more burgers later.
Brown patties on both sides in a lightly oiled skillet. Then pour the stock into the skillet and bring to a boil. Reduce heat and simmer, covered, for 25 minutes.
Serve on buns with all your burger fixings. Serve with a veggie or salad. Enjoy!