Kebabs: 1) Smash the garlic cloves, sprinkle with a generous pinch of salt and, with the flat side of a large knife, mash and smear the mixture to a coarse paste. Mix the paste and the remaining salt with the meat, onion, parsley and spices.
2) Line a pan with aluminium foil. Divide the meat mixture into 28 rough balls. Mould each piece around the pointed end of a skewer (if you use wooden ones, soak them in water for 15 minutes before use), making a 5-cm oval kebab that comes to a point just covering the tip of the skewer. Lay the skewers on the pan, cover and refrigerate for at least 30 minutes and up to 12 hours.
3) Heat a griddle pan over medium heat or prepare a barbecue. Brush the pan lightly with olive oil. Working in batches, cook the kebabs, turning occasionally, until brown all over and just cooked through, about 6 minutes. Transfer to a serving platter and serve with tzatziki and flat bread.
Tzatziki: 1) If you're using natural whole milk yoghurt, line a small sieve with a coffee filter. Put the yoghurt in it, set it over a bowl and refrigerate for 12 hours. Discard the expressed liquid and put the yoghurt in the bowl.
2) Grate the cucumber on the large holes of a box grater into another bowl. Sprinkle with salt and rub the salt into the cucumber with your hands. Set aside for 20 minutes then squeeze the cucumber to express as much liquid as possible.
3) Smash the garlic, sprinkle with a generous pinch of salt, and, with the flat side of a large knife, mash and smear the mixture to a coarse paste. Stir the cucumber, garlic, olive oil, lemon juice and mint into the yoghurt. Refrigerate for at least 1 hour before serving.