In a large bowl, combine the yoghurt, tandoori spice blend, lemon juice, garlic, and salt. Mix well to combine.
Add the chicken thighs to the bowl and toss to coat with the marinade. Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or overnight if possible.
When ready to cook, preheat your grill to medium-high heat.
Remove the chicken from the marinade and discard any excess marinade.
Grill the chicken for about 5-6 minutes per side, or until the internal temperature reaches 165°F (75°C).
Once cooked, remove the chicken from the grill, wrap it in tin foil and let it rest for a few minutes before slicing.
Serve the tandoori chicken hot, with a mint raita dip garnished with chopped cilantro if desired.
Enjoy your delicious and flavourful tandoori chicken with some basmati rice and mint raita sauce. Yummy!