Douse mushrooms in water. Peel potatoes and dice them. Cut peeled onion and the bacon into cubes. Heat oil in a saucepan and sauteé onion and bacon until translucent.
Douse with soup and add potatoes, spices and squeezed out mushrooms. Boil the soup until the potato pieces are al dente.
Season with salt and pepper and serve garnished with parsley.