Boil the potatoes for about ten minutes, or until a kitchen fork jabbed into the biggest potato slips out when you lift the potato out of the water. Rinse the potatoes in cool water to stop further cooking.
Slice the potatoes first from end to end, then into half-discs about a half-inch thick.
Heat half the butter in a skillet over medium-high heat until it bubbles, and sauté the onions until they just begin to brown at the edges.
Add the potatoes, green onions, and the remaining butter to the pan and cook, without stirring, until the potatoes have browned on the bottom. Turn the potatoes over and brown the other side. Add Creole seasoning to taste.