Cook potatoes with skin in boiling water for about 20 minutes. In the meantime take the chicken meat out of the paella and pluck it into small pieces. Remove the skin from the chorizo and cut the sausage into slices.
Rinse anchovies, dab dry and cut finely. Peel and finely chop the onions.
Drain the potatoes, rinse with cold water and allow to cool slightly. Then peel and slice.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Heat oil in a large ovenproof pan. Brown the chorizo in it and take it out. Sauté potatoes in hot frying fat.
Fry the onions briefly. Season with salt and pepper. Add chorizo, paella and anchovies to the pan and mix well. Whisk eggs, salt and pepper. Pour over the tortilla.
Bake in a hot oven for 20-25 minutes. Wash parsley, shake dry and chop finely. Remove the paella from the oven and serve sprinkled with parsley. Tastes also good cold - cut into large cubes and serve as tapas.