Method

• Melt the butter in a saucepan and once it starts to foam, add the leeks, shallots, garlic and chestnuts and sauté over a high heat for 6-7 minutes or until golden brown
• Add the sherry and let it bubble, stirring and scraping the base to remove all the sediment stuck on the bottom
•   Boil rapidly over a medium heat until the sherry has reduced and become syrupy
• Add the stock, cover and bring to the boil, then reduce the heat to a gentle simmer, remove the lid and simmer until the sauce has slightly thickened
• Add the cream and simmer until well combined and thickened
• Blend until smooth and creamy
• Return to the heat and serve