Slice the potatoes and onions; add them to the meat liquor, with the butter and pepper and salt to taste, and boil gently for one hour.
Then rub the soup through a wire sieve.
Put it into the saucepan again, and, when boiling, shake into it the semolina and cook for fifteen minutes, stirring occasionally.
When the semolina is cooked the soup is ready.
If this soup is used for children, water may be substituted for the meat liquor if the latter is not available.