Heat the oil a saucepan over a medium heat. Add the garlic, leek and ground ginger and gently fry for 2-3 minutes, until the leeks have softened.
Add the carrot and the stock, bring to the boil, then reduce the heat to simmer for ten minutes, or until the carrot is cooked through.
Place the soup into a food processor and blend until smooth, then season, to taste, with salt and freshly ground black pepper.
To serve, place the apple into a warm bowl and pour in the soup.