Prepare the mushrooms: If using King Oyster mushrooms, shred them lengthwise using two forks to create thin strips resembling meat fibers. If using other types, slice them thinly.
Mix the marinade: In a bowl, combine the olive oil, lemon juice, apple cider vinegar, smoked paprika, cumin, coriander, turmeric, garlic powder, onion powder, cayenne pepper (if using), cinnamon, salt, and pepper. Whisk well.
Marinate the mushrooms: Add the prepared mushrooms to the marinade. Toss until every piece is coated. Cover the bowl and refrigerate for at least 1 hour, or up to 4 hours for deeper flavor.
Cook the mushrooms: Heat a large skillet or cast-iron pan over medium-high heat. Add the marinated mushrooms in a single layer, avoiding overcrowding the pan. Cook in batches if necessary.
Sear the mushrooms: Cook for 5 to 7 minutes per side, stirring occasionally, until the mushrooms are deeply browned, slightly crispy at the edges, and have released most of their moisture. This searing process develops the savory, meat-like texture.
Assemble the shawarma: Warm the pita bread. Fill each pita with the cooked mushroom shawarma. Top with tahini sauce, chopped tomatoes, sliced onions, fresh parsley, and pickles.
Serve immediately.
Notes
King Oyster mushrooms provide the best texture for this recipe due to their dense flesh.
For a richer flavor, you can roast the mushrooms on a baking sheet at 400°F (200°C) for 20 minutes, flipping halfway, instead of pan-frying.
Tahini sauce recipe: Whisk 1/4 cup tahini paste with 2 tablespoons lemon juice, 1 clove minced garlic, and enough cold water (about 3-4 tablespoons) until smooth and pourable.