Wash and rinse red chilliies. Cut its slits.
Cut from centre vertically. Remove its seeds.
Add saunf, ajwain, methi dana, mustard seeds in a grinder. Grind in a coarse powder.
Shift in a bowl. Add all dry ingredients on it. Mix all properly. Adjust salt according to your taste.
Now take mustard oil in a bowl. Keep it aside. Let glass jar be ready for storing pickle.
Stuff above masala in red chilli and dip it in oil. Keep it in jar.
Repeat this process for all chillies. Now add remaining oil over it.
Close the lid of jar.
Keep it in sun light for 4-5 days.
If it looks dry then add some more mustard oil.
After 5 days red chilli pickle is ready to serve. Enjoy spicy and tangy pickle whole year.