Mix the tikka masala paste and the natural yoghurt in a large, non-metallic mixing bowl. Add the chicken thighs and turn to coat. Cover and marinate in the fridge for at least 30 minutes or overnight.
For the salsa:
Toast the cashew nuts in a dry frying pan, stirring often until golden brown. Allow them to cool then roughly chop and mix with all the remaining salsa ingredients except the mini pappadums.
For the raita:
Combine all of the raita ingredients in a separate bowl and season lightly.
BBQ method: If using a barbecue, put the chicken thighs over a medium-hot area, brush thickly with the marinade, season, and cook for about 20 to 25 minutes, turning occasionally until they are cooked through.
Oven method: Alternatively, cook the chicken pieces in an oven preheated to 200 C / 180 C fan / Gas 6 and bake for 45 minutes until cooked through and the chicken is no longer pink.
Stir the crushed pappadums into the salsa and serve with the chicken and the raita. Garnish with fresh mint.