Lamb Shawarma Sandwich

Ingredients

• Lamb
• 1 pound boneless lamb shoulder (or boneless, skinless chicken thighs), thinly sliced
• 2 medium onions, thinly sliced
• ¼ cup extra-virgin olive oil
• Juice of 1 lemon
• ½ teaspoon ground allspice
• ½ teaspoon ground cinnamon
• ¼ teaspoon Lebanese 7-Spice Mixture
• A few sprigs fresh thyme, leaves only
• Sea salt and finely ground black pepper
• Tahini Sauce
• ½ cup tahini
• 2 cloves garlic, minced to a fine paste
• Sea salt
• Sandwiches
• Three 8-inch round pita breads
• 4 to 6 small firm-ripe tomatoes, thinly sliced
• 1 small red onion, halved and cut into very thin wedges
• 4 to 6 gherkins, thinly sliced lengthwise
• Handful of mint leaves
• A few sprigs flat-leaf parsley, leaves only