Take a bowl, add cherry tomatoes, some salt, 1 tbsp oil, black pepper powder. Toss it and grill them for 5 to 7 minutes.
Heat pan and dry roast mustard seeds, fennel seeds, carom seeds together. Let it cool down and put it into the blender and coarsely ground it.
Heat oil in a pan. Now add grilled tomatoes, salt (if required), grounded spices, chopped mint leaves, sugar and vinegar. Mix well and switch off the gas.
Once it is cooled down, store it into the air tight container.