Preheat oven to 375 degrees F.
Start by creaming 1 stick (1/2 cup) butter with 1/3 cup brown sugar and 1/3 white sugar (superfine sugar, if you have it). Add 1 egg and blend thoroughly. Stir in 1 1/2 cups flour and 1 teaspoon baking soda.
Add about 7 ounces of chocolate chips.
You could use chocolate bars chopped into chunks instead, if you wish. Spoon onto a baking sheet and bake for 10-12 minutes.
Take out of the oven and cool on a rack.