Melt the chocolate in the top of a
double boiler, or in a heatproof bowl set over a pan of gently simmering
water. Set aside.
In a bowl, sift together the flour and
salt. Set aside.
Cream the butter until soft. Add the
sugar and continue beating until the mixture is light and fluffy. Mix
the eggs and vanilla essence, then gradually stir into the butter
mixture. Stir in the chocolate, then the flour. Finally, stir in the
nuts.
Divide the mixture into four equal
parts, and roll each into a 5cm diameter log. Wrap tightly in foil and
chill or freeze until firm.
Preheat the oven to 190oC/375oF/Gas
5. Grease two baking sheets. With a sharp knife, cut the logs into 5mm
slices.
Place the circles on the baking sheets
and bake until lightly colored, about 10 minutes.
Using a palette knife, transfer to a
wire rack to cool.