These tacos mix India's tikki masala chicken with classic Greek toppings like tzatziki, cucumber, and red onion for a taco like you've never had before.
In a medium bowl, mix the tzatziki, chopped cilantro, cardamom, and coriander. Add 1 to 2 tbsp. water if needed to loosen the sauce; season with salt and pepper.
In a medium deep skillet with a lid, heat the oil over medium-high. Season the chicken and add to the skillet. Cook the chicken until golden brown, about 5 minutes per side. Pour the tikka masala sauce over the chicken. Bring to a simmer. Cover and reduce heat to medium-low. Simmer the chicken, turning once, until cooked through, 20 to 25 minutes. Transfer the chicken to a cutting board; using 2 forks, shred into bitesize pieces. Return the chicken to the sauce to keep warm.
In a skillet over high heat or over a gas flame on the stovetop, using tongs, char the tortillas, turning often, about 15 seconds per side.
Divide the chicken among the tortillas. Top with the tzatziki sauce, cucumber, and onion. Garnish with cilantro leaves and the chile.