|Unsalted butter||3 1⁄2 Ounce (100 Gram)|
|Salted butter||3 1⁄2 Ounce (100 Gram)|
|Icing sugar||5 Ounce (140 Gram)|
|Dark brown sugar||7 Ounce (200 Gram)|
|Plain flour||14 Ounce (400 Gram)|
|Soda bicarbonate||1 Teaspoon|
|Dark chocolate||10 1⁄2 Ounce (300 Gram)|
|Blanched almonds||7 Ounce (200 Gram)|
|Walnuts||7 Ounce (200 Gram)|
Preheat the oven to 180°C (350°F), gas mark 4.
Warm both types of butter and mix together with the icing sugar and brown sugar.
Add the flour and bicarbonate of soda (if used), and then incorporate the eggs.
Chop the chocolate and roughly chop the almonds and walnuts using a knife or food processor, then add to the mixture.
Shape the dough into regularly shaped 'sausages' about 5 cm/2 inches in diameter and chill in the refrigerator for 2 hours.
Cut the dough into slices about 1 cm/ 1/2 inch thick and place on a baking sheet lined with nonstick baking parchment.
Bake in the preheated oven for 20-25 minutes.
Remove from the baking sheet and leave to cool on a wire rack.
To keep the cookies crisp, store in an airtight container.