Hand grind if possible, under a stone, the ingredients for best results. If not available use mixie. Put the garlic, ginger, green chilli first. Add the vinegar and remaining spices, a little at a time while grinding. Grind till coarse paste is made. Heat oil, add masala, a little at a time. Fry till brownish in colour.
Add tomatoes and salt, bring to boil. Cool and preserve in clean glass jar.