BBC Food - Recipes - Make-ahead Christmas gravy

Ingredients

• 1 tbsp light olive oil or vegetable oil
• 3 carrots , peeled and roughly chopped
• 1 red onion , cut into wedges
• 5 chicken wings
• 1 large glass white wine (optional)
• 1-2 tbsp cornflour , depending on how thick you like your gravy
• 2 litres/3½ pints chicken or turkey stock (from 2 stock cubes or jelly pots)