To make the Master Stock, put all the ingredients into a large pot, except the potatoes and oil, and bring to a boil.
Peel the potatoes and cut into halves or quarters, and put into the Master Stock. Cook the potatoes for about 15-20 minutes, until you can easily pierce the potatoes (without them falling apart).
Preheat oven to 180°C/160°C. Using a wire scoop, remove the potatoes from the Master stock and allow to cool. Reserve the stock for uses.
Place the potatoes on a baking sheet, in a single layer. Drizzle a generous amount of oil, using your hands, mix together so the potatoes are coated in oil. (You could do this in a separate bowl, but then you have extra dishes to wash)...
Roast the potatoes for 30 minutes, or until they are golden and crispy. Serve with roast chicken or roast duck. Garnish with thinly sliced green onions.