Preheat the oven to 200°C/400°F. Combine garlic granules, ground cumin, smoked paprika, dried oregano, onion powder, ground coriander, ground cinnamon, salt, and black pepper in a mixing bowl.

Heat a frying pan over high heat. Sear the 600 g oyster mushrooms under a heavy pan or weight for 4 to 5 minutes.

Turn the mushrooms and sprinkle both sides with about half of the spice mixture. Continue searing for 4 to 5 minutes until golden brown.

Juice the lemon into a mixing bowl. Whisk the remaining spice mixture with 4 tablespoons olive oil and 2 tablespoons maple syrup or agave syrup.

Coat the seared oyster mushrooms thoroughly with the lemon-spice marinade. Thread the mushrooms onto 4 skewers, using red onion pieces as a stable base.

Place the mushroom skewers on a baking tray. Roast for 30 minutes at 200°C/400°F.

Brush the mushroom shawarma with remaining marinade every 10 minutes. Roast until the edges are browned and lightly crisp.

Slice the tomato, cucumber, red onion, and fresh parsley. Slice the roasted mushroom shawarma from the skewers into thin pieces.

Warm the 4 flatbread wraps in a dry frying pan. Spread each wrap with vegan tzatziki and tahini.

Divide the sliced mushroom shawarma and salad vegetables among the wraps. Fold the wraps tightly and serve immediately.