Crush all the marinade ingredients in a mortar and pestle until coarse.

Trim the lamb of excess fat and season with salt and pepper. Generously rub the prepared marinade on the lamb shoulder on both sides. Leave to marinate on the counter for an hour, preferably overnight in the fridge.

Preheat the oven to 160°C / 325°F / Gas Mark 6.

In a large roasting pan, add the roasting veggies. Add a few sprigs of thyme, rosemary, and parsley. Place the garlic and lemon halves around the veggies. Season with salt and pepper. Place the marinated lamb shoulder on top of the veggies.

Pour the stock and red wine around the shoulder over the veggies in the roasting rack.

Place the crumpled parchment paper over the lamb shoulder, then tightly cover the roasting pan with aluminum foil. Place the roasting rack on the middle rack in the oven.

Roast the lamb shoulder for 4 to 6 hours until fork tender. Remove from the oven and leave to rest covered.

Transfer the meat and veggies to a serving platter. Use the roasting pan to make the gravy.

Place the roasting pan on medium-low heat and add the flour and broth. Deglaze the pan, scraping as much as possible. The flour will thicken the gravy.

Strain the gravy through a mesh sieve to remove all the excess bits and pieces from the roasting pan.

Serve with the lamb over mashed potatoes, lemon rosemary roast potatoes, lemon dill potatoes, potato wedges, and a side salad.