In a blender add ginger, green chillies,mango pulp/puree besan/chickpea flour,yogurt/dahi, turmeric powder, red chilli powder(optional) and 1.5 cup of water.
If adding mango pieces, puree first before adding with yogurt and besan.
Blend to smooth mixture. Make sure there are no lumps in mixture.
Heat 1 tbsp of oil in a kadhai/heavy bottomed pan.
Add ½ tsp of Cumin seeds and Fenugreek Seeds. Once the seeds crackle, add blended yogurt mixture.
Keep on stirring the mixture on medium flame, till it boils.
Lower the flame and then cook it for 10-15 mins. till it starts getting thick in consistency.