Cut chicken into stripes and leeks into rings. Remove the skin, seeds and fibres from your pumpkin. Cut the flesh into bite-size pieces. Heat oil in a pot and fry chicken stripes until golden brown. Season with salt and pepper and lift out meat. Add leeks and pumkin cubes and sweat them. Sprinkle with curry and douse with soup. Let all simmer for 5 minutes. Blend thoroughly sour cream with cornflour and thicken vegetables. Add chicken stripes, warm up and season to taste.