01 - Preheat your oven to 425°F. Line a baking sheet with parchment paper.
02 - In a large mixing bowl, whisk together the flour, baking soda, and salt.
03 - Make a well in the center and pour in the buttermilk. Mix gently with a wooden spoon or your hand until a shaggy dough forms. Do not overwork.
04 - Turn the dough out onto a lightly floured surface. Knead briefly, just until it comes together. Shape the dough into a round loaf about 2 inches thick. Place on the prepared baking sheet.
05 - With a sharp knife, cut a deep cross into the top of the loaf about ½ inch deep.
06 - Bake for 35–40 minutes, or until the loaf is golden and sounds hollow when tapped on the bottom.
07 - Cool on a wire rack for at least 30 minutes before slicing. Serve warm or at room temperature with generous slabs of Irish butter.