Wash the apple thoroughly, rub dry and quarter it. Remove core, cut apple into pieces. Clean, wash and cut leek into rings. Cut sausages into pieces and fry them all around in hot oil.
Add apple and leek and fry for about 2 minutes. Remove everything from the pan. Pour on 200 ml water and stir in Fix für Currywurst with a whisk. Let it boil for about 1 minute. Add sausage, apple and leek again and heat up briefly.
For the mashed potatoes, boil 150 ml of water and milk. Add peas and heat briefly. Remove the pan from the heat and stir in the puree powder. Season with salt. Wash parsley, dab dry and chop.
Sprinkle over the ragout.