Mix the tikka masala marinade ingredients together. I used a mild curry paste, you could also use a medium or hot one if you're in the mood.
Slice your choice of vegetables and use your hands to rub the marinade all over them. The quantity of vegetables is pretty flexible, I used 1 eggplant sliced about 1.5cm or half an inch thick, 2 red capsicums cored and cut into wedges, 1 courgette cut into thick slices and 3 large button mushrooms cut in half. I could probably have included a bit more without having to increase the quantity of marinade used.
Mix the coconut yoghurt and grated cucumber together, season with salt to taste and refrigerate until you're ready to serve.
Heat the barbecue grill to medium/high and cook the vegetables, starting with the eggplant about five minutes before everything else as it takes longer to cook. Add the other vegetables, then cook them until they have char marks and are cooked to your liking.
Serve vegetables hot off the grill with cooked basmati rice or quinoa, a big dollop of coconut yoghurt and some fresh coriander (cilantro). Add some cashew nuts or Indian bread on the side if you like.