Put the potatoes in a large pan, cover with water, add a little salt and bring to the boil. Cook for 10-15 mins or until tender. Drain and set aside half for tomorrow. Return the rest of the potatoes to the drained pan with 1 tbsp of the oil, the garlic, preserved lemon and cumin. Keep warm while you cook the lamb.
Rub the lamb chops with the remaining oil and season. Heat a griddle pan and cook for 3 mins each side or until cooked to your liking. Season the potatoes and stir in the mint, then serve with the griddled lamb and peas or salad.