To begin, boil the amlas until they are soft. If you are using a pressure cooker, give it about four whistles.
De-seed and divide them into sections. Crush them coarsely keeping a few sections intact.
Heat mustard oil to smoking point and let it cool down a bit.
Add in the mustard seeds (sarson), fenugreek seeds (methi dana), and fennel seeds (saunf). Allow them to splutter.
Add in the crushed amlas and chopped green chillies. Mix well and saute.
Next, add in the dry masalas - salt, black salt or kala namak, black pepper powder, cumin powder (jeera), Kashmiri red chili powder, and a pinch of hing (asafoetida). Saute for a few minutes.
Add in brown sugar and white vinegar. Cook on medium to low heat until the sugar melts and oil starts appearing on the sides.
Finally, add in the crushed cardamoms and garam masala powder. Mix well.
The Sweet & Spicy Amla Chutney is ready to serve. Enjoy with puris or parathas.