Given the task definition and input, reply with output. In this task, you have to identify the named entities (NER) which are the ingredients required given its directions. Named entities are the names of the items without their quantity.

Put first 4 ingredients into large pot. Add 1 can water and boil mixture., Mix hamburg, pork, bread, egg, salt, pepper and parsley and form into small meatballs., When pot is boiling, add meatballs and gently fold them in., Cook slowly about 4 hours; add salt and pepper if needed., Serves 4 to 6 people., Freezes well.
celery, parsley, onions, tomatoes, hamburg, ground pork, bread, egg, parsley