In a frying pan add some oil and fry off the steak canadians from frozen until cooked through (should only take a few mintues)
shred the lettuce, slice and half the cucumber.
Cut the pitta bread in half
In a separate bowl mix a small amount of garlic puree/powder (to your taste) with some mayonnaise.
Add a splodge of the garlic mayonnaise in the bottom of each pitta, then add a portion of lettuce and cucumber, then add a slice or two of the steak canadians and top with the sweet chilli sauce and extra garlic mayo.