Polish Sausage (Kielbasa) Soup

2 tablespoons butter
1 1/2 lbs lean fresh kielbasa or 1 1/2 lbs smoked kielbasa, sliced
1 cup chopped onion
2 cups chopped celery
4 cups shredded cabbage
2 cups sliced carrots
1 bay leaf
1/2 teaspoon dried thyme
2 tablespoons white vinegar
3 cups beef broth
2 cups water
3 cups peeled and cubed potatoes
salt and pepper
Garnish
chopped fresh dill (optional)
Melt butter in a large skillet, add sausage, onions and celery, and cook over medium heat until sausage are lightly browned.
Pour mixture into a soup pot and add remaining ingredients except for potatoes.
Bring to a boil, reduce heat, cover and simmer for 1 hour.
Add potatoes and cook until potatoes are tender.
Season with salt and pepper and garnish with dill, if desired.