Hearty Cabbage Soup

2 tablespoons butter
1/2 large onion, diced
1 celery stalk, diced
2 cups shredded cabbage
3 potatoes, peeled and cut into medium cubes
6 cups chicken stock
1/2 tablespoon dried dill
2 tablespoons flour
1/2 cup sour cream
1 tablespoon milk

Heat butter in large saucepan over medium heat. Add onion, celery and cabbage; season well. Partly cover and cook 10 minutes over low heat. Add potatoes, chicken stock and dill; and salt and pepper to taste. Stir and bring to boil and continue cooking, partly covered, 20 minutes over low heat. Mix floer with sour cream and milk in a small bowl. Add to soup stock. Mix well, heat and serve. Enjoy!