Tread lamb, mushrooms and onion alternately onto skewers.
Combined stock, wine, oil, worcestershire sauce and rosemary in a large, non-metallic, rectangular container and season with pepper.
Add lamb skewers to marinade. Cover and marinate in the fridge for at least 2 hours, turning occasionally.
Remove skewers from marinade and cook over a medium-high heat on a pre-heated BBQ, char-grill plate or frying pan for 3-4 minutes each side or until cooked to your liking.