Dry-roast the coriander and cumin seeds. Skip this step if using spices that have already been roasted.
Roast the Byadagi chillies in 1 tsp oil. Skip this step if using chillies that have already been roasted in oil.
Hand-pound the roasted spices in a mortar and pestle, or use a spice grinder. Add the jaggery, turmeric and salt, then pound further to make a coarse mixture.
Add around 2 tbsp of the spice mix to the thin poha. Add the freshly grated coconut and mix well by hand. Add more spice mix and coconut if desired.
For the optional tempering, heat oil in a small pan. Add the mustard seeds, urad dal, Byadagi chilli and curry leaves. Pour the tempering over the poha mixture.
Serve immediately after mixing, with a banana on the side if desired.