Ordering caviare demonstrates greed (7)
I believe the answer is:
avarice
'greed' is the definition.
(avarice is a kind of greed)
'ordering caviare' is the wordplay.
'ordering' indicates anagramming the letters.
'caviare' with letters rearranged gives 'AVARICE'.
'demonstrates' acts as a link.
(Other definitions for avarice that I've seen before include "A deadly sin" , "Insatiable desire for wealth" , "Wanting to be rich" , "Greed for gain" , "excessive desire for wealth" .)