Ingredients
Method
- Assemble ingredients

- Melt butter over low heat and add flour to form a roux. Cook gently for one minute

- Take of heat and add stock. Whisk to remove any flour lumps. Bring to boil and then simmer
- Whisk in horseradish, mustard and lemon juice. Return to simmer
- Add sour cream
- Adjust seasoning. Serve

