For the marinade, tear the wild garlic or peel the garlic cloves, then use a pestle and mortar to smash it up with the fennel seeds and some sea salt and black pepper.
Mix with the lemon zest and about 80ml of olive oil, or until you get a good consistency to coat the lamb.
If using rosemary skewers, remove the leaves, apart from 2cm at the top, then sharpen the opposite ends so you can pierce the meat. Otherwise, soak the wooden skewers in warm water for at least 20 minutes before using.
Cut the lamb into 5cm pieces, peel and slice each onion into 6 wedges, then place in a large baking tray. Add the cherry tomatoes and mix with the marinade.
Thread, alternating ingredients, onto the skewers, then refrigerate until ready to cook.
Pick and finely chop the mint leaves and mix with the yoghurt, a pinch of salt and pepper, a squeeze of lemon juice and a splash of extra virgin olive oil.
Preheat the barbecue, grill or griddle pan. Grill the kebabs, turning occasionally, for about 7 minutes, or until evenly cooked and crisp and golden on all sides.
Serve with a drizzle of extra virgin olive oil, a squeeze of lemon juice and the minty yoghurt.