Soak ker and sangria in 1 cup of beaten yogurt overnight.
The next morning take them out of the yogurt and wash under running water.
Boil them in 2 cups water and salt for 15-20 minutes.
Cut red chillies in small pieces and remove seeds.
Cut dried mango into smaller pieces.
Heat oil in a non-stick kadai.
Add cumin seeds and red chillies and sauté till fragrant.
Add ginger paste and mix.
Add a little water, turmeric powder, red chilli powder, coriander powder, dried mango pieces and mix well.
Add remaining yogurt and mix.
Drain and add ker and sangria and mix well.
Add amchur and mix and cook till the moisture evaporates.