Transfer the aubergine to a baking dish and turn the oven up to 220C/fan 200C/gas 7. Heat a frying pan to very hot and add the cutlets (if using lamb rumps add them fat-side down) to the pan. turn the cutlets over after a minute and give them another minute on the other side. Lift them onto the aubergine slices and put into the oven for 5 minutes. If using lamb rumps, then turn them so they brown well all over, lift them onto the aubergine and cook for 12-15 minutes, or until a skewer pushed into the centre comes out feeling hot. Rest for 10 minutes. Serve the lamb with the salsa.