What are the uses of tzatziki sauce? I normally add tzatziki sauce when I eat roast left-overs. I cut the roast in slices (without warming it), and I add some tzatziki sauce.

Are there different uses for tzatziki sauce?  (I am sure there are.)
You can use it on its own as a dip with pita bread, use it as a spread on sandwiches, or as an accompaniment to fish and meat as you're already doing.