recently I got by ILL the book "Gulaschkanone The German Field Kitchen in WW II and Modern Reenactment" by David L Thompson who bought and restored a German WW II era field kitchen. It has also sorts of info on its operation accessories, recipes ect. Note the German WW I field kitchen was almost identical to the one used in WW II.
Two versions of the Feldküche were provided to the army that went to war in 1914. The cavalry version had just one lidded well on the right side of the "cooker", while the infantry version had a well on either side. A third and smaller version used by the KuK was produced by a German manufacturer too.
These field kitchens proved a boon to soldiers after a hard day of movement and fighting during the advance. Mornings usually would find them serving coffee and bread in the wee AM hours. Compare that to the French system that required each rifle squad to carry their own cooking ware. Later, as was the norm, the allies copied the vehicle; as it would seem they were always 3-4 months behind German battlefield innovations.
The Russians, of course, had field kitchens in the field with all their armies with the start of hostilities.
