Soften the butter by leaving it out of the fridge and bringing it to room temperature. Melt the chocolate in a small bowl over simmering water. Let the chocolate mixture cool before adding to the butter.
Lightly cream the softened butter by hand (a wooden spoon or fork works best), or beat it with an electric beater.
Add the cooled chocolate, icing sugar, vanilla essence, salt and nuts. Mix all ingredients together until well-combined.
Let mixture stand for an hour to marry the flavours.
Pile the butter into cling film or waxed paper, shape into a sausage and roll the film around the sausage, twist both ends and refrigerate until firm.
Just before serving, cut butter into disks, remove film from discs and place atop warm food at the last minute and let it melt.
Notes & Tips
If 1 cup of icing sugar is too sweet for you, feel free to reduce the amount.