Heat some oil in a pan in low flame. Add grated ginger to the oil when a little warm.
Add finely chopped green chillies and saute well.
Now add in the chopped fresh coriander leaves and keep stirring.
After about a minute add fresh or frozen green peas and stir.
Sprinkle in some salt, red chilli powder, coriander powder and dried mango powder to it and mix well.let it cook for 2-3 minutes.
Put the mashed boiled potatoes in , mix well and let it cook for about 3-5 minutes.
Take it off heat and keep aside. The samosa filling is ready.