2 tbsp eachcoarsely chopped flat-leaf parsley and oregano 3 tsp eachcoarsely chopped thyme and rosemary2large garlic cloves2 tbspextra-virgin olive oil2lamb racks (650gm each)4Desiree potatoes, cut into 1cm-thick slicesTo serve:lemon wedgesQuince in cider vinegar1 kgcaster sugar3quince1bay leaf250 mlapple cider vinegar
For quince in cider vinegar, bring sugar and 800ml water to the boil in a wide saucepan over high heat. Peel quince and cut each into 6 wedges, remove seeds (leaving core intact), and place in syrup. Bring to the simmer, then place a round of baking paper directly on quince and weight with a plate. Cook over low heat with barely any bubbles until starting to colour (2 hours; see note). Remove quince from syrup and transfer to 2 sterilised 1-litre jars. Add apple cider vinegar to syrup and bring to the boil, then pour over quince, leaving 1cm air at the top of jars. Seal jars and set aside to cool completely. Quince will keep refrigerated for 2 weeks. Bring to room temperature to serve.
Pound herbs and garlic with a mortar and pestle to a coarse paste, add 1 tbsp oil and season to taste. Score lamb racks and rub thoroughly with herb mixture and set aside to come to room temperature.
Preheat oven to 180C. Place potatoes in a roasting pan lined with baking paper and brush all over with remaining oil. Heat a frying pan over high heat, add lamb and cook, turning occasionally, until browned on all sides (2-3 minutes), then place in pan with potatoes and roast until potatoes are golden and tender when pierced with a skewer and lamb is cooked to your liking (20-30 minutes for medium-rare). Set aside to rest, covered loosely with foil (20 minutes).
Cut lamb into cutlets and serve with potatoes and quince in cider vinegar.
Note Quince can sometimes take many hours to
colour; keep the liquid barely simmering and continue cooking until
they turn a deep blush pink.