Pickle Red Onion: Thinly slice the red onion and place it in a small bowl. Pour in red wine vinegar and sprinkle with kosher salt, mixing well. Let them pickle for at least 15 minutes.

Make Honey-Harissa Glaze: In a small bowl, combine harissa, honey, and fresh lemon juice, stirring until well mixed. Set aside to allow flavors to meld.

Prepare Halloumi: Slice the halloumi cheese into thick pieces, about half an inch. Pat dry with a paper towel.

Cook Halloumi: Heat a skillet over medium-high heat, drizzle in olive oil, add halloumi slices, and cook for 1-2 minutes until golden. Flip, add honey-harissa glaze, and cook an additional minute.

Prepare Salad: In a mixing bowl, combine pickled onions, diced cucumbers, cherry tomatoes, dill, minced garlic, olive oil, salt, and pepper. Toss until well mixed.

Assemble Pitas: Toast pita breads until warm. Spread tzatziki inside, fill with halloumi and salad mixture, and serve immediately while warm.