Wash and dry produce.

Halve, peel, and thinly slice half the onion (whole onion for 4 servings). Quarter lemon. Trim and quarter cucumber lengthwise; cut crosswise into ¼-inch-thick pieces.

In a small microwave-safe bowl, combine sliced onion, juice from half the lemon, and a pinch of salt. Cover with plastic wrap; microwave until softened, 30-40 seconds. Uncover and stir, then set aside to pickle.

Transfer cucumber to a separate small bowl; season lightly with salt and pepper.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add beef*, ketchup, raisins, Shawarma Spice Blend, a big pinch of salt, and pepper.

Cook, breaking up meat into pieces, until cooked through, 4-6 minutes.

Meanwhile, wrap pitas in damp paper towels; microwave until warm and pliable, 30-40 seconds. Halve pitas; gently pull apart to create pockets. TIP: Halve pitas one at a time to make opening easier and prevent sticking.

In a third small bowl, combine mayonnaise, sour cream, and juice from one lemon wedge (two wedges for 4 servings). Taste and season with salt and pepper.

Fill pita halves with beef. Top with seasoned cucumber, white sauce, pickled onion (draining first), and as much hot sauce as you like.

Divide pitas between plates. Serve with tortilla chips and any remaining lemon wedges on the side.