Boil 2-3cups water in a large pot
Add dry mushrooms and simmer. Add fresh mushrooms and drained canned mushrooms. Add vinegar
Salt and pepper to taste

Take sour cream (room temperature) and mix with flour to make a paste in a separate bowl.
Spoon some hot broth into the sour cream paste to dissolve. Add to mushroom pot
Salt and pepper to taste

Boil potatoes and cook steak to preference. Add to soup bowl before serving