01 - Place diced potatoes in a large pot and cover with cold water. Bring to boil over medium-high heat, add pinch of salt, and cook 12–15 minutes until fork-tender.
02 - Drain potatoes thoroughly and return to hot pot for 1–2 minutes to evaporate excess moisture.
03 - Mash potatoes until completely smooth and free of lumps.
04 - While potatoes remain warm, add butter and mash until melted and fully blended.
05 - Stir in flour, salt, and pepper. Mix with wooden spoon, then knead briefly by hand until soft but not sticky. Add extra flour if necessary.
06 - Turn dough onto lightly floured surface. Pat or roll to ½-inch thickness. Cut round into quarters for four triangular farls, or halve quarters for smaller pieces.
07 - Heat nonstick skillet or griddle over medium heat. Cook farls in batches 4–5 minutes per side until golden brown and crisp.
08 - Serve warm, generously spread with salted butter.