Slow Cooker Chicken Shawarma

Ingredients

• 2 pounds boneless, skinless chicken thighs
• 4 cloves garlic, minced
• 1 tablespoon ground cumin
• 1 tablespoon ground coriander
• 1 tablespoon ground paprika
• 1 teaspoon ground allspice
• 1 teaspoon turmeric
• 1 teaspoon ground cinnamon
• 1 teaspoon cayenne pepper
• Salt
• black pepper
• 1/4 cup fresh lemon juice
• 1/4 cup olive oil
• 1 large onion, thinly sliced
• Pita bread or flatbread, for serving
• Sliced cucumbers, tomatoes, red onions, and lettuce, for garnishing
• Tzatziki or tahini sauce, for drizzling