Slice the halloumi into 1cm thick strips and pat dry with a paper towel to ensure a crisp sear.
Heat olive oil in a non-stick pan over medium-high heat.
Fry the halloumi slices for 2 to 3 minutes per side until golden brown and crispy, seasoning with dried oregano while cooking.
Warm the pita breads in a separate dry pan or oven until soft and pliable.
Spread a generous portion of tzatziki sauce across the center of each warm pita.
Layer the fried halloumi, sliced tomatoes, red onions, and cucumbers on top of the sauce.
Garnish with chopped parsley and fold the pita tightly around the filling.
Serve immediately while the cheese is still warm.