400 gmkipfler potatoes, scrubbed and halved lengthways3Spanish onions1head of garlic, cloves separated100 mlolive oil1dried chorizo, skin removed, finely chopped100 gmcoarse fresh breadcrumbs2 tbspcoarsely chopped oregano1lemon, finely grated rind and juice only1egg1boned chicken2 tbspsherry vinegar125 ml(½ cup) chicken stock
Preheat oven to 200C. Cook potatoes in a large saucepan of boiling salted water until par-cooked (7-8 minutes). Drain and set aside.
Meanwhile, finely chop 1 onion and 1 garlic clove. Heat 2 tbsp oil in a small saucepan over medium heat. Add chopped onion and garlic and cook until soft (4-5 minutes). Transfer to a bowl, add chorizo, breadcrumbs, oregano, lemon rind and egg, season generously to taste and, using your hands, combine well.
Place boned chicken, skin-side down and with shortest side facing you, on a clean work surface. Spread over chorizo mixture, then roll away from you into a tight sausage shape. Secure at intervals with kitchen string, season to taste and set aside.
Cut remaining onions into wedges and combine with reserved potatoes, remaining garlic cloves, vinegar and 2 tbsp olive oil in a small roasting pan. Pour over lemon juice and stock and season to taste. Place chicken on top, drizzle with remaining oil and roast until golden (40-45 minutes). Serve rolled chicken thickly sliced with pan vegetables and juices.