Start by slicing the bitter gourd and sprinkling some salt over it. Let it rest for 2 hours to remove excess bitterness and rinse with water.
After that boil enough water in a pan on high heat and add sliced bitter gourd and salt. Cook for 2 minutes and stir in between.
Strain them. Squeeze the bitter gourd well and dry it in the sun for 4-5 hours until pat dry the karela.
Make sure that you grate the mango in a little bit thick grater.
Add grated ½ cup of raw mango and ½ tsp salt in a bowl and cover it with a lid. Keep it aside for 4-5 hours.
After that Squeeze the grated mango and dry it in the sun for 4-5 hours until pat dry the raw mango.
Take a big bowl, add dried bitter gourd/karela, dried raw mango, mustard oil, fenugreek seeds, fennel seeds, turmeric powder, red chili powder, coriander powder, nigella seeds (kalaunjee), salt (adjust as per taste).
Mix all the ingredients well.
Transfer this karela pickle to the glass or ceramic bottle and let the pickle for about 2 weeks. After 2 weeks, the bitter gourd pickle is ready to eat.
Store in an airtight jar and enjoy with your favorite meals!