Heat oil in a large pot. Braise the chopped onion and garlic. Once braised, pour in 6 1/5 cups (1.5 liters) of hot water and add the cleaned and chopped potatoes.
Boil them until soft, add the crushed broth and cleaned and chopped sorrel and dock.
Boil the soup for a few minutes and add spices to taste.
Take off from the heat and blend everything in the pot well.
Finally, mix the soup with the whipped cream.
Optionally, serve the soup with croutons or hard-boiled eggs.