When it simmers once reduce the flame and boil kachalu for 6-8 minutes more. Turn off the gas and when all pressure escapes take them out so that they cool down completely. Peel and cut them in medium size pieces.
Take mustard oil in a pan and let it get hot completely (this helps remove the sharpness of the oil). Turn of the gas and let the oil get cool down a bit. Now on low flame add carom seeds, kalonji and fenugreek seeds in the oil and sauté it for few seconds. Also add kachalu pieces, asafoetida, turmeric powder, red chilly powder, mustard powder, and salt. Mix all ingredients nicely. Stir constantly with help of a spoon for 2 minutes and then turn off the gas.
When pickle cools down also add vinegar and mix gently. Kachalu pickle is ready. It can be served now or serve it after 3 days till then it will taste more awesome as all spices will get mixed nicely. Stir the pickle daily with a clean and washed spoon.
It can be stored for up to 15-20 days.
Always use clean and dry spoon for stirring the pickle. Before taking out pickle stir it nicely as all spices and oil settles at the bottom of the container and the upper layer remains dry. This increases the shelf life of pickle.