Close lid. Cook for 2 minutes. Stir. Add salt, stir. Close lid and cook till soft and all water evaporates. Let it cool.
Roast coriander seeds if you choose to use seeds.
In a blender, add coriander seeds first. Grind them to powder. Then add raw mango, cooked brussels sprouts. Grind coarsely. Add salt if needed. If you are using coriander powder instead of seeds, add it now. Pulse to mix well. Remove into a bowl.
If you think spice level isn't enough, you can add red chilies in tampering.
Now prepare for tampering. In a small tampering Kadai, add remaining oil. Heat to medium.
Add red chilies. Cook until brown.
Add black mustard seeds. When they start spluttering, add cumin. Cook until golden brown.
Add curry leaves. When they stop spluttering, add turmeric.
Turn off the stove, add hot tempering to the chutney.
Serve with rice, quinoa. You can also use as a spread on your sandwich.
Recipe by Ujwala's Delicacies at https://www.ujwalasdelicacies.com/brussels-sprouts-raw-mango-chutney/