In a large pan, add the chicken wings, carrots and celery (cut into small chunks), spring onion, parsley, salt and pepper and water and bring to the boil.
Simmer for 2 hours, skimming the surface regularly. The water should reduce to two-thirds.
Strain stock through a sieve and discard the rest.
Heat in a pan and add the white wine, gravy salt and gradually stir in cornflour until thickened.
Serve with your selected meat, potatoes and vegetables.