Preheat the oven to 180*c, and line a tray with baking paper. Sift 2 cups of plain flour, one teaspoon of baking soda and one and half cups of sugar into a bowl. Rub in 90 grams of soften butter, mix in 120 grams of chocolate chips and stir in half a cup of milk until the mixture turns into dough. Use a table spoon to drop balls of dough onto the tray, about a cm apart. Bake for 15-20 minutes.