Wash and dry poblano green chillies.

Make cut in centre of each chilli from one side only.

Heat mustard oil and switch off flame and leave it to cool slightly.

Grind mustard seeds and fennel seeds.

Mix all dry ingredients in a plate well.

Add some oil in these dry ingredients and mix well.

Fill this mixture in chillies and pour rest of oil and mixture on chillies. Keep it for one week before use.