In a bowl, mix 500 grams of boneless chicken pieces with 2 tablespoons of yogurt, 1 tablespoon of ginger-garlic paste, 1 teaspoon of red chili powder, 1 teaspoon of garam masala, 1 teaspoon of cumin powder, 1 teaspoon of coriander powder, 1/2 teaspoon of turmeric powder, salt to taste, and 2 tablespoons of oil. Marinate for at least 2 hours or overnight for better results.
Heat a pan and cook the marinated chicken on medium heat until fully cooked and slightly charred. Set aside.
In a separate bowl, prepare the sauce by mixing 1/2 cup of mayonnaise, 2 tablespoons of tahini, 1 tablespoon of lemon juice, 1 clove of minced garlic, and salt to taste.
Warm 4-5 flatbreads (preferably pita or roti) on a tawa or in a microwave.
Assemble the rolls by spreading a generous amount of sauce on each flatbread, adding sliced onions, tomatoes, cucumber, and cooked chicken. Optionally, you can add some chopped lettuce or pickled vegetables.
Roll the flatbread tightly and wrap it in foil or parchment paper to hold its shape. Serve immediately or grill the rolls for a few minutes on a tawa for a crispier texture.