Preheat oven to 150 C / Gas 2.
Sieve together the flour, baking powder and salt, set aside. In a medium bowl, cream the butter and sugar together until fluffy. Gradually stir in the dry ingredients, then stir in the walnuts and chocolate chips.
Roll or scoop dough into walnut sized balls. Place them on ungreased baking trays 3cm apart. Flatten biscuits slightly. Bake for 15 to 20 minutes, until light golden brown. Remove from trays to cool on racks.