Ingredients:
Raw mangoes - 2 cups
Salt - As needed (Approximately 3 tbsp)
Gingelly Oil - 1/4 cup
Black mustard seeds (kaduku) - 2.5 tsp
Fenugreek seeds (uluva) - 1 tsp
Asafoeitida - 1 tsp powder or 1/4 inch piece
Red chilli powder 2-3 tsp
Method:
Wash and dry raw mangoes. Cut the mango into small pieces and remove the pit. Add salt to the cut mango pieces. Mix well and transfer to a sterilised bottle. Set aside for 2 days. water start coming out making mangoes soft.
Dry roast 2 tsp mustard seeds, fenugreek seeds and asofoetida piece and powder it together. Take care not to burn the spices. You can make it a finer powder or leave it a bit coarse . 
To the salted mangoes bottle and this ground powder, chilli powder ,salt and mix well. stir vigorously for 5 seconds.Adjust chilli powder and salt to your preference. Don't be stingy on the salt though, it acts as a preservative. Also, if you like a fiery red pickle add Kashmiri chilli powder like I did.
Heat oil in a pan on medium flame. When the oil becomes room temperature, add to the bottle of mango pieces and mix well. If not U can mix all in a separate pan also.When cool close the lid and keep for a week so that the masala get absorbed to mangoes.
.......And there Cut Mango pickle is ready. Serve with rice and curd.
