First thing, preheat your oven to 425°F (220°C). We are gonna give this bread a nice crusty finish after pressure cooking.
Grab a big bowl and toss in your flour, salt, sugar, and baking soda. Stir it up so it’s all mixed well.
Next make a well right in the middle and crack in your egg. Pour the buttermilk in too and mix it all up until just combined. Don’t overdo it, you want it a bit shaggy.
Add in the melted butter and currants if you fancy them. Fold those in gently so you still have some texture.
Lightly flour your surface. Dump the dough out and knead it for about a minute, just enough to bring it all together.
Shape your dough into a nice round loaf. Place it on a parchment-lined baking sheet. This dough's gonna slide around less.
Take a sharp knife and cut a deep cross on top of the dough. This is old school but it works real good for soda bread.
Pop it into the oven and bake for about 30 minutes or until it’s golden and a toothpick comes out clean. Let it cool on a wire rack before slicing so you don’t squish that lovely crumb.
Store your buttermilk in a jar with a spoon of lemon juice if you ain’t got buttermilk. Let it rest while you prep other ingredients.