How do you make sour schi?

Looking for a hangover cure? lol … 2 lb sauerkraut; drained and cut into cubes 1 carrot; peeled and grated 2 onions; peeled and minced 1 cup + 1 lt water 1 cup dry mushrooms; soaked 1 bunch parsley; coarsely chopped 10 peppercorns 1 tbsp flour 3-4 tbsp vegetable oil Sugar Salt

• Put first 4 ingredients in a large saucepan and simmer, covered, for about 1 and a half hours.
• Bring 1 lt water to a boil and add mushrooms - simmer for 1 hour; drain but do not discard the water. Cut the mushrooms into strips.
• Heat 1 tbsp oil in a skillet and toss in mushrooms and parsley; cook about 2 minutes.
• Add the mushroom water to the sauerkraut mixture and bring to a boil; add mushrooms.
• In a small pan, cook the flour dry until hot and add a little mushroom broth to dissolve, whisking constantly; continue adding broth, a little at a time, until the liquid is creamy.
• Add creamy flour mixture to the large saucepan and stir well.
• Add sugar and salt to taste.
• Bring to a boil, then remove from heat.
• Let sit, covered, for at least one hour.