In a large bowl mix together the garlic, onion, parsley, thyme, rosemary and basil, seasoning, oil, bay leaf, lemon juice and white wine. Add the lamb shoulder, coat well and marinate in a fridge for twelve hours.
Wash the potatoes and cook for 15 minutes in a pan of salted boiling water until they start to become tender, they need to stay quite firm so don’t overcook them. Remove the shoulder from the marinade and place in a roasting tin, add 125ml water. Reserve the marinade liquid for cooking.
Preheat the oven to 200°C. Slow cook the lamb basting with the marinade regularly over the 2 hours. Add a little more liquid to stop the dish from drying out. 30 minutes before the end of cooking, toss the potatoes in olive oil and roast in the oven with the lamb. Serve the shoulder of lamb on a bed of roasted baby potatoes.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.