Aam Ka Achar,

Ingredients
Raw Mangoes - 2, large, wash, pat dry, cut into small pieces, wipe with a clean cotton cloth
Mustard oil - 200 ml
Mustard seeds - 1 tbsp
Fenugreek seeds - 1 1/2 tsps
Nigella seeds - 1 1/2 tsps
Fennel seeds - 2 1/2 tbsps
Asafoetida - 1/4 tsp
Salt - 1 1/2 tbsps (can increase by 1/2 tbsp)
Turmeric powder - 1 tsp
Red chili powder - 1 1/2 tbsps (can increase by 1/2 tbsp)

Method
Sun dry mustard seeds, fenugreek seeds, nigella seeds and fennel seeds separately for a day.
Heat 100 ml of mustard oil till smoking point and turn off flame. Bring to room temperature.
Coarsely crush fennel seeds and mustard seeds. Set aside.
Place the cut green mangoes in a wide vessel. Add turmeric powder and salt and mix well.
Add the crushed spices, nigella seeds, fenugreek seeds, asafoetida and red chili powder and mix well.
Add the room temperature mustard oil to the vessel and mix well. Cover with a muslin cloth and place in the sun for a day.
Remove the mango pickle from the vessel and place in a glass jar.
Next day heat 100 ml mustard oil till smoking point and turn off flame. Bring to room temperature. Add the cooled mustard oil to the mango pickle and mix well. Ensure that the mango pieces are immersed in a layer of mustard oil.
Allow the mango pickle to mature by placing the pickle jar in the sun for a week. The pickle can be stored upto a year.
Aam ka achar is ready for consumption from day 8. Serve with roti, paratha or mathri.