Add the onion, garlic and potatoes to the base of a slow-cooker (needs to be a minimum of 6.5 litres/6 quarts). Pour in the stock and lemon juice.

Rub the lamb all over with the salt, pepper, dried oregano and olive oil. Place the lamb on top of the vegetables in the slow-cooker.

Cover and cook on low for 10–12 hours, or until the meat is tender and falling off the bone (see note 1).

Preheat the oven to 220°C (425°F) (200°C/400°F fan-forced).

Remove the lamb from the slow-cooker and place in a roasting pan (you can line the roasting pan with baking (parchment) paper to help with clean-up – it also presents beautifully at serving time). Reserve 1 cup (250 ml) of the juices from the slow-cooker, avoiding the fat. Pick out the potatoes from the slow-cooker and place them around the lamb (it’s okay if some break apart – they will just get extra crispy!).

Drizzle the lamb with the extra 1 tablespoon of olive oil. Bake in the oven for 20–25 minutes, or until crisp and browned.

Add the butter to a saucepan over medium heat. Once melted, add the flour and stir for 1–2 minutes until a thick paste has formed.

Whisk in half of the reserved slow-cooker juices and, once incorporated, whisk in the remaining half, followed by the beef stock, continually whisking. Season to taste with salt and pepper.

Simmer for 4–5 minutes until thickened. Strain the gravy through a sieve and set aside in a gravy boat or small bowl.

Use tongs or two forks to shred the lamb and serve it with the potatoes, gravy and fresh oregano leaves (if using) and serve with steamed greens.