Sauerkraut Soup

This is Lisa Joy's recipe. She says it is best reheated 1-2 days later.

4 liters water                                       

2 lbs sauerkraut                                                        
2 handfuls dried mushrooms                                     
4 chicken bouillon cubes                                           
1 Tbsp paprika  (imported is best)                                                      
10 black peppercorns                                               
salt to taste  
1 lb kielbasa, cut into small disks
5 - 6 potatoes 
2 Tbsp olive oil
1 onion, chopped
3 cloves garlic, minced
1 Tbsp flour                                     
1/2 cup cold water
sour cream for garnish

Add water, sauerkraut, mushrooms, bouillon cubes, paprika and salt (I added 2 tablespoons of parsley) to a large pot and bring to a boil. Simmer over medium heat for 15 minutes.
Add kielbasa and potatoes and simmer another 10-15 minutes.
Meanwhile saute onion and garlic in olive oil until onion is golden. Sprinkle flour in and combine, stirring constantly for 30 seconds. Add cold water and stir until smooth. Add to soup.
Bring to a boil, then simmer until potatoes are fork-tender.
serve with a dollop of sour cream