Pre-heat the oven to 180 degrees/gas 5. Lightly grease 2 baking trays.
Measure the butter and sugars into a bowl and beat thoroughly until evenly blended. Add the beaten egg.
Mix in the flour then stir in the chocolate chips. Spoon large teaspoons of the mixture on to the prepared baking trays, leaving room for the cookies to spread.
Bake in a pre-heated oven on the top shelf for 8-10 minutes or until the cookies are golden. Keep a close on eye on them to make sure they do not burn.
Leave the cookies to cool on the trays for a few minutes then lift off with a palette knife.