potatoes until water is clear, then drain and squeeze dry. Place them in a mixing bowl, add onion, flour and eggs and mix everything well. Add salt and crushed black peppercorns and mix well.
Heat sufficient oil in a
12-inch non-stick skillet over moderately high heat until hot but not smoking. Put 2 tbsps of potato mixture per hash brown in skillet, spreading into 3-inch rounds with a fork. Reduce heat and cook till undersides are browned or for about 5 minutes. Flip them and cook till the other side is similarly browned. Drain them on absorbent paper.
Add more oil to skillet
as needed and cook more hash browns in the same way.
Arrange them on
serving plates, sprinkle chaat masala (if using), garnish with spring onion greens and serve.