For the potato soup, clean the greens and boil them with the veal bones in 1.5 l of salted water. Strain, add the diced potatoes to the soup and cook until soft.
Make a roux with flour and fat, add finely chopped onions and chopped parsley. Dilute the roux with a little cold water and add to the soup, mix very well and cook. Before serving, stir in the sour cream.
Preparation Tip:
The potato soup can still be sprinkled with roasted bacon cubes.