Soak the skewers over night to stop them from burning.
Place all the ingredients for the marinade in a bowl with 1 teaspoon of salt. Mix well, pour over the pork and leave in the fridge, covered, for 2 hours or overnight.
Preheat the oven to 200C.
Skewer the pork whilst heating up your ridged grill plate, making sure to ventilate your kitchen. Ideally you would use a BBQ to grill the pork but a ridged grill plate works well.
Place the skewers in batches on the grill and cook for 5 minutes, turning so that all sides are nicely charred. Transfer to a large baking tray, 30 by 40 centimetres, and finish cooking in the oven for 20 minutes, until the meat is cooked through and tender.
To make the yoghurt sauce, mix the courgettes with ¼ teaspoon of salt and leave to drain for 5 minutes. Gently squeeze out the excess liquid and place in a medium bowl. Stir through the yoghurt, oil, garlic, lemon juice and ¾ of a teaspoon of salt. Place the butter in a small pan and cook on a medium heat until it bubbles, turns a light golden brown and has a nutty aroma. Remove from the heat, set aside for 5 minutes to cool and then stir into the yogurt. Sprinkle a little dried mint on top of the yoghurt and keep in the fridge until ready to use.
To make the salad, place the garlic, chopped onion, oil and vinegar in a pestle and mortar with ¾ teaspoon of salt. Crush to make a paste and set aside. Place the sliced onions in a large bowl with the cucumber, peppers, nigella seeds and the paste. Mix the dill and mint in just before serving, alongside the skewers and yogurt sauce.