Soak the dried mushrooms in 1/2 cup of warm water for 1 hour. Saut# mushrooms and onion in butter in a skillet 3 minutes. Add sauerkraut to mushrooms; cook and stir for 10 minutes. Blend 1/3 cup water into flour. Mix with sauerkraut and simmer for 15 minutes. Season to taste with salt and pepper. I usually like to add 1/4 cup of dark rum after cooking.