Sieve the flour into a mixing bowl and then rub in the margarine until the mixture resembles fine breadcrumbs. Stir in the sugar and dried fruit, or whichever additions you are using.
Add the beaten egg and milk to the bowl a little at a time, stirring gently, until you get a sticky consistency. Spoon the mixture onto greased baking trays in ten small splodges. They will spread out when they cook so make sure you leave space between each one.
Sprinkle the top of each one with sugar. Bake the rock cakes at 220°c for 15 minutes until golden brown. Leave to cool slightly before enjoying. Simply serve warm with a pot of tea.