Yogurt-Marinated Lamb Skewers

This is my signature, fail-safe lamb kebab recipe. It’s such a crowd-pleasing favourite, that no matter how much I make, the skewers always disappear in minutes. The recipe works just as well with baby lamb rib chops; but there is something incomparable and visually irresistible about aromatic, charred chunks of meat waiting to be plucked off of obliging skewers. This kebab is terrific paired with warm pita bread and any of my cool, crunchy side salads—
Radish Salad with Dried Mint 
Cucumber Radish Salad with Ginger and Green Chillies 
Jicama-Mango Salad
Pear and Watercress Salad with Szechwan Peppercorns 

Ingredients 

2 lbs [1 kg] boneless leg of Lamb, cut into 2-inch-thich pieces
Six 12-inch-long Skewers*

Marinade: 

1 small Onion, peeled and quartered
5–6 cloves Garlic, peeled
2-inch piece Ginger, peeled
½ cup plain, unsweetened Yogurt (preferably a strained, Greek-style yogurt)
2 tbsp ground Coriander
1 tsp ground Cumin
1 tsp ground Garam Masala
1 tsp Chilli powder
¼ tsp freshly ground Black Pepper
Salt (to taste)
Juice of ½ lemon (reserve the squeezed lemon piece—rind, pith, and pulp—cut into quarters, for use in the marinade)

1. Put onion, garlic, and ginger in a food processor and grind to a smooth paste. Transfer paste to a large mixing bowl, large enough to accommodate the marinade and lamb. 
2. Add remaining marinade ingredients to bowl, except the quartered lemon pieces, and stir to incorporate. Add lamb and mix well with marinade. Tuck in the quartered lemon pieces into the meat, cover the bowl will plastic wrap, and refrigerate for at least 3 hrs, or up to 1 day. Prior to cooking, remove lamb from fridge, thread meat pieces onto skewers, and bring to room temperature.
3. Pre-heat a charcoal/gas grill or grill-pan on medium for 25 mins. Turn the heat to high 5 mins before cooking. When the grill surface is smoking hot, add skewers, and let grill on their first side for 3 mins, or until well charred. Then gently turn every 2 mins until the remaining sides are well caramelised. 
4. Remove skewers onto a platter and let sit for 5 mins before serving. 

*TIP: If you are using wooden skewers, soak them in water for ½ hour prior to cooking, to prevent them from singeing on the grill.