Roast cumin seeds in a dry frying pan until fragrant, then grind finely.
Finely chop onion, garlic, cumin, paprika and juice of one lemon in a hand mixer, add yogurt and fold in.
Place meat cubes in a large enough bowl and pour marinade over them and mix through. Leave at room temperature for at least 2 hours or refrigerate overnight.
Thread drained chicken onto wooden skewers. Sprinkle with salt and pepper and grill over charcoal (about 6 minutes on each side). Serve with lemon wedges.
Tip: Use creamy natural yogurt for an even finer result!