We always eat this with yakhni pulao. It’s another one of those family things, and a favourite. Feel free to modify the sweet-sour-pungent profile to your taste!
Boil the whole tomatoes in water on medium high heat till the outer skin cracks. Let cool.
Once cool, peel the tomatoes and mash them roughly with a fork.
Add in the chopped onions, ginger, salt, sugar, vinegar/lime juice, mustard, and the optional green chilli. Let it sit for a while, at least ten minutes.
If the tomato is bland, my MIL would add a dash of tomato ketchup. Adjust the seasonings to your taste and mix in the chopped coriander just before serving.
Refrigerate leftovers