Whisk the flour, egg, salt and milk until smooth and stand for at least 5 to 10 minutes. Put a teaspoon of oil into four individual tins or half a spoonful into eight tartlet tins and heat in the oven for at least five minutes. When they are really hot, pour in the batter. Set oven to gas mark 7 for 15 minutes until golden. Serve immeadiately