In a pot, cover completely with water and bring to a rolling boil;1-2pounds of whole potatoes (if there is a gap in sizes split the larger ones to cook evenly)1 teaspoon kosher salt
Cook until tender, a knife easily inserts to the center, remove from heat, drain the water and place uncovered in the fridge to cool. They will cut much easier when fully chilled, so this might be an item to prep the night before.
Split the potato lengthwise, place face down and split again lengthwise. Turn that ninety degrees and cut into 1/4 slices, you now have roughly quarter circle slice.
Heat a large skillet to medium high, add 2 tablespoons oil, onions and potatoes. Move them around regularly, cooking until the spuds are golden and the onions are soft. Serve and add salt and pepper to taste. If you fancy an O’Brien potato add some finely diced green and red bell peppers toward the end of the cooking.