Add about ½ inch water to a large dutch oven pan. Bring water to a boil.
Add sliced cabbage to the water. Cover and cook over medium heat until cabbage is soft. About 15-20 minutes.
Place sauerkraut and 2 cups water in another saucepan and bring to a boil.
Season cubed pork shoulder with salt and pepper.
In a large skillet over medium heat, melt butter. Fry seasoned pork shoulder until browned.
Add fried pork shoulder to the cabbage in the dutch oven.
In the same skillet over medium heat, fry the bacon until it renders it's fat.
Add sliced Kielbasa, diced onions and minced garlic to the skillet. Cook until onions are soft.
Add sauerkraut with liquid, cooked bacon, Kielbasa, onion and garlic to the cabbage in the dutch oven.
Stir in tomato paste and add bay leaves.
Simmer for 1-2 hours until pork is cooked through and liquid in the pot cooks down.
Ladle stew into large bowls and serve with a loaf of freshly baked bread.