Step 1: In a large bowl, combine the Greek yogurt, minced garlic, grated ginger, garam masala, turmeric, ground cumin, ground coriander, chili powder, salt, and black pepper. Mix until well combined and fragrant.
Step 2: Add the chicken pieces to the yogurt mixture, ensuring each piece is thoroughly coated. Cover the bowl and refrigerate for at least 30 minutes, but ideally 2-4 hours, or even overnight for the best flavor and tenderness.
Step 3: Preheat your oven to 400°F (200°C) or prepare your grill for medium-high heat. If using the oven, line a baking sheet with parchment paper or foil for easy cleanup.
Step 4: If baking, arrange the marinated chicken in a single layer on the prepared baking sheet, leaving a little space between pieces. If grilling, thread the chicken onto skewers, ensuring not to overcrowd them.
Step 5: Bake for 20-25 minutes, or grill for 8-12 minutes, turning occasionally, until the chicken is cooked through and has a nice char on the edges. The internal temperature should reach 165°F (74°C). Broil for the last 2-3 minutes if you desire extra browning and char.
Step 6: While the chicken cooks, warm your tortillas. You can do this in a dry skillet over medium heat for about 30 seconds per side, wrap them in a damp paper towel and microwave for 30-60 seconds, or wrap them in foil and warm in the oven.
Step 7: Prepare your desired toppings: shred some cabbage for a crisp slaw, chop fresh cilantro, dice red onion, and prepare a simple yogurt-mint sauce (mix plain yogurt with fresh mint, a squeeze of lime, and a pinch of salt).
Step 8: Assemble your Chicken Tikka Tacos: spoon a generous amount of chicken tikka onto each warm tortilla, top with your favorite fresh toppings, and drizzle with the yogurt-mint sauce. Serve immediately and enjoy!