"Dumplings are globular masses of boiled or steamed dough.  This is a food with few, indeed no, social pretensions, and of such simplicity that it may plausibly be supposed to have evolved independently in the peasant cuisines of various parts of  Europe and probably in other parts of the world too.

Dumplings added to the soup or stew, are still, as they were centuries ago, a simple and economical way of extending such dishes. 

The dough for most dumplings has always been based either on a cereal, or on  one of the vegetables from which a bread dough can be made or partly made (potato, pulses, etc.) 

In the region of Bavaria, Austria and Bohemia, the common material of dumplings is stale bread.  This is broken into small pieces and soaked in water or milk, and combined with any available enriching ingredients: bacon, eggs, cheese, chopped liver, or herbs.  There are sweet types stuffed with fruit.  In some of the more refined kinds flour or semolina or,  since the 19th century,  potatoes are used in the basic mixture.

Steamed dumplings are cooked in a shallow bath of milk in a tightly lidded pan.  The heat transmitted through the bottom of the pan browns the undersize of the dumpling, which rests on its bottom.  The steam above the milk, slightly superheated by pressure due to the close-fitting lid, hardens and browns the top.  The middle, surrounded by boiling milk, which transmits less heat to it than does steam, remains soft and extensible so that the dumpling rises and, and when cooked, has a brown top and bottom and a soft, white central zone.