Peel, wash and slice the potatoes. Fry the potatoes in two pans in hot oil for about 15 minutes. Peel onions, cut into fine slices and fry them after 10 minutes. Put them into an ovenproof dish (approx. 20 x 30 cm)
Beat the eggs. Season vigorously and pour evenly over the potatoes. Place in a hot oven (electric cooker: 200 °C/recirculating air: 175 °C/gas: level 3) for 15-20 minutes and allow to cool
Cut the ham in half lengthwise. Finely slice the parmesan. Cut tortilla into approx. 24 cubes. Stick the parmesan, olives and ham on top