Preheat the oven to 160°C. Like a large baking tray with baking paper.  

Place garlic, onion, fennel and rosemary on the baking tray. Pour over the stock and season with a good pinch of salt and pepper. Place the lamb on top and season with salt, pepper and the Greek herbs. Rub well and cover with a sheet of baking paper, then wrap the whole tray with foil.  

Bake for 3-4 hours until lamb is tender. 

Place the potatoes and 1 tsp of salt in a medium saucepan and cover with water. Bring to the boil over high heat. Turn down to simmer and cook until the potatoes are soft enough to pierce them with a fork.  

Drain the potatoes and place onto another baking tray lined with baking paper. Flatten the potatoes using a small plate, drizzle with olive oil and season with salt, pepper and rosemary.  

Remove the lamb from the oven, place all the onion, fennel, garlic flesh and cooking juices into a saucepan add the potatoes. And place the lamb back onto the baking tray.  

Turn oven up to 220°C and place the potatoes into the oven to roast for 25 minutes, adding the lamb back into the oven after 15 minutes, until both are browned and crisp.  

To the saucepan with the vegetables, add the mustard, honey and preserved lemon. Blitz using a stick blender until smooth. Place over low-medium heat and stir, until warmed through.  

Add the roasted potatoes into a large bowl with the cucumber, parsley and tzatziki.  

Spread the gravy at the bottom of a platter, place the shoulder on top and sprinkle with chives. Serve with the crispy potato salad.