In a large bowl, combine chicken, tandoori paste and yoghurt together. Cover to leave to marinate in the fridge for 3-4 hours.
When ready to cook the chicken, take out of the fridge and bring up to room temperature (about 30 minutes).
Meanwhile, make the raita. Dice the cucumber and mango/pineapple; finely dice the red onion and chilli. Mix cucumber, mango/pineapple, red onion and chilli with mint, coriander, yoghurt and lime/lemon juice. Season to taste with salt and pepper, and a little more juice if needed.
Preheat barbecue or oven grill to high. Season chicken well with salt and drizzle with a little oil. Cook for 2-3 minutes on each side until cooked through. Set aside to rest for 5 minutes.
Slice chicken and serve with raita and naan bread or rice on the side.
Tandoori paste
Mix 1 ½ tsp ground cumin, 1 tsp ground coriander, ½ tsp ground chilli, 1 ½ tsp smoked paprika, 1 tsp ground turmeric, 4 cloves minced garlic, 2 Tbsp tomato paste and 2 Tbsp oil together. Makes approximately ¼ cup.