Slice jalapeños with the seeds. Be sure to wear gloves so you don't regret it later ;)
Add salt, turmeric powder and ground muster seeds to the sliced jalapeños.
Add juice of 2 fresh limes to it and mix it well with a spoon.
Heat oil in small pan. Once its nicely hot, CAREFULLY add that to the jalapeños mix. Mix everything well with a spoon.
Store this pickled jalapeños in the mason jar and keep it in the fridge. Keep shaking it once a day for 2-3 days. They last for 3-4 weeks if you keep them in the fridge!
They go so well with curry/subzi and rice, roti, wraps, eggs etc.