Add the butter to a pan and turn the heat onto medium. Once melted, add the onion and grate the garlic in too.
Once the onions have sweated down, add the chicken livers, tomato purée, mace, nutmeg, bayleaf, brandy, port, salt, pepper and double cream.
Mix all the ingredients together for 5-10 minutes until the chicken livers are cooked through.
Either blend all the ingredients together or pour the contents into a blender and blitz until smooth.
Divide the mixture between 6 ramekins
Cover with the melted clarified butter and place a sprig of thyme on top.
Refrigerate for 2 hours or overnight. Serve chilled