Wash green chilies and slice horizontally into small round rings.
Heat mustard oil in a pan until smoking, crackle mustard seeds and coarsely crushed fennel seeds.
Add sliced green chilies, turmeric powder, and salt.
Sauté on medium-low flame for 4 minutes until chilies soften slightly.
Stir in amchur powder, cook for 1 minute, and serve as a side condiment.