[Taqwus]

A size N unit (hoburg=1, human infantry=2, human cavalry=3, giant=4, Moloch might be 5, dragon=6) consumes N-1 supply per turn, except for size-1 units (which consume a full 1) and non-eating units.

Cauldron of Broth = 50 supply units; twice as much as a wine bag in the same number of misc slots. There's also the Summer Sword, which provides something like 25 supply. The same commander having multiple supply items of the exact same type does NOT stack; use different items or spread them among commanders. These supply numbers are reflected in reduced supply consumption in that province instead of higher available supplies.