We couldn't find buttermilk but the recipe we used said that if you couldn't find it, you could sour whole milk with lemon juice. That's what we did, and I think it worked fine. The other ingredients are plain flour, salt, and bicarbonate of soda. You simply sieve the flour, salt, and bicarb, and then pour in the milk. Stir until it's a sticky dough. Put it on a flour dusted baking tray and then cut a very deep cross into the dough. This helps the heat penetrate right to the middle of the dough, to cook it through at the same rate that the outside cooks. We dusted some flour on top, too.
We baked it on gas mark 4 for 30 minutes. That seriously seemed to be all it needed - it came out looking well. We left it to cool for a few minutes then sliced off a small slice to taste and share. It's quite salty - I think next time I would put less salt in. The texture is quite cakey and doughy, I think it would be really nice with jam spread on top!
We used this recipe here, it's good.
Pouring the soured milk into the flour and other dry ingredients
The dough all ready on the tray, but before we cut the cross
And this is after baking! Doesn't it look lovely? The cross lets the dough stretch