Heat oil in a pan and sauté the onions till golden brown. Add the ginger garlic paste and cinnamon fry for some time. Add the chilly powder, cumin powder, turmeric powder, sugar and tomato puree and fry till the oil separates from the masala. Now add the vinegar and a little water and bring to boil. Reduce heat and simmer till the gravy is sufficiently thick. Cut the boiled eggs into halves and carefully drop into the gravy. Simmer for a few minutes. Take out the egg halves and place on a serving dish. Pour the thick gravy over the eggs and shake the dish so that all the eggs are covered with the gravy. Serve hot.