01 - In a large mixing bowl, combine the Greek yogurt, lemon juice, tandoori masala, ground coriander, ground cumin, paprika, turmeric, garam masala, cayenne pepper (if using), salt, minced garlic, grated ginger, and vegetable oil. Stir until all ingredients form a smooth, well-blended paste.
02 - Add the cubed chicken pieces to the marinade and toss until every piece is evenly coated. Cover the bowl with plastic wrap and refrigerate for at least 1 hour, or up to overnight for deeper flavor penetration.
03 - Preheat an outdoor grill, oven broiler, or stovetop grill pan to high heat. If using wooden skewers, ensure they have been soaked in water for at least 30 minutes beforehand to prevent scorching.
04 - Thread the marinated chicken pieces onto skewers, leaving a small gap between each cube to allow even cooking on all sides.
05 - Place the skewers on the hot grill and cook for 8 to 10 minutes per side, turning occasionally, until the chicken is cooked through (internal temperature reaches 165°F) and develops appealing char marks.
06 - Transfer the skewers to a serving platter. Garnish generously with fresh cilantro leaves and accompany with lemon wedges. Serve immediately while hot.