Place all sauce ingredients into a sauce pan. Bring to a boil. Reduce heat and simmer while preparing the other ingredients.
Put water in a pot large enough to hold the cabbage leaves without tearing them. Start heating the water to a boil.
Heat a frying pan on medium heat. When hot, add a small amount of olive oil. When oil is shimmering. add leeks. Cook until soft, about 4 minutes.
Add mushrooms and walnuts to pan with leeks. Cook until the mushrooms are soft, about 8 minutes.
Add beans to frying pan. Mix well, turn heat to medium low. After the beans are hot, about 3 minutes, remove the mixture from the heat and set aside.
While the beans are heating, the water should be boiling for the cabbage leaves. Place the leaves in the boiling water and gently press them to submerge them. Cook them until soft, about 5 minutes. Immediately remove and submerge in cold water to stop them cooking and make them handleable.
Turn heat off on the cranberry sauce. Use a potato masher, if desired, to pop more of the cranberries, depending on how many have popped. Some whole ones are fine.
Place 2 cups of the cranberry sauce in a cast iron skillet and spread evenly over the bottom of the pan.
Place several spoonfuls of the bean mixture in each cabbage leaf and roll. Place each roll in the pan.
When the pan is full, pour sauce over the cabbage, leaving some aside for serving the cabbage rolls.
Place the pan on medium low for half an hour.
Put one or two rolls on a plate and top with reserved sauce.
Enjoy!