Drain your can of sardines.
Slather the tzatziki over the pita, then top with the mixed greens, cucumbers, tomatoes, olives, red onion, and capers.
Top the pita off with the contents of the sardine can. You can place the fillets on whole, or roughly chop them them place them on.
Feast on the pita as is, or carefully roll it up with foil and enjoy it like a gyro!