Sift flour, salt, sugar & baking soda together a few times to mix the thoroughly. Make a well in the centre & stir in the buttermilk gradually to make a soft dough. Turn out on a floured board & knead lightly for a few minutes. Flatten it out to about 1/2" thick. With a floured knife, cut a cross on it to help it cook evenly throughout.
Bake at once in a hot oven (450F, Gas 8, 230 °C) for 45 min. To test whether the cake is done or not, tap the bottom - if cooked it should sound hollow.
