Peel the onions and cut them into very thin slices. Heat a large non stick pan and add 2 tbsn cooking oil. When the oil is hot add the onions and stir fry them until golden brown. Add more oil if needed. Then add salt, crushed red chillies, chopped garlic, curry leaves and a little red chillie powder and stir well. Now add tamarind juice and cook until browned, stirring occasionally. Lastly add sufficient sugar, stir well and remove from heat.
You can enjoy this with milk rice or can use as a filling for buns.