Puree the tomatoes with the water and set aside.
Heat the oil. Add the mustard seeds. Cover the saucepan until the mustard seeds stop popping. Then roast the following 6 spices and the ginger in it for 1 minute.
Add the tomatoes, the asafoetida and the salt. Simmer gently at medium temperature for about 20-30 minutes until a thick sauce is formed. Add the sugar, increase the temperature and make it in about 5 more min, stirring continuously.
Remove the cloves, bay leaves and cinnamon stick.
Either pour directly hot into small jars or cool to room temperature to serve with a snack or meal at the table.
Diana Thrush:
You can get black mustard seed in all Asian stores. It is also not expensive at all.
Tip: Always use aromatic spices to refine your dishes!