Heat the butter in a pan over a medium heat and add the shallot.
Cook for a few minutes, stirring occasionally until the shallot has softened but not coloured.
Next, add the garlic and minced truffles and cook for a minute so that the garlic and truffles can release their flavour.
Pour in the brandy and allow it to reduce for a minute.
Add the cream and bring to a simmer.
Depending on how thick you like the sauce you can simmer until the cream thickens for a few minutes or mix a teaspoon of cornflour with water and stir in.