01 - Place the potatoes in a pot of cold, salted water. Bring to a boil and simmer for 12-15 minutes, or until fork-tender. Drain well and allow to steam dry for 2 minutes.
02 - Mash the potatoes thoroughly until smooth. While still warm, mix in the butter and salt.
03 - Add the flour and gently knead until a soft dough forms. If the dough is sticky, add a little more flour as needed.
04 - Turn the dough onto a floured surface. Divide in half, then shape each half into a flat, round disc about 1/2 inch thick. Cut each round into 4 equal wedges.
05 - Heat a heavy-based frying pan or griddle over medium heat. Lightly grease with a little butter. Cook the farls in batches for 3-4 minutes per side, until golden brown and cooked through. Serve warm.