Gundruk is fermented green vegetable (leaves). Allow mustard, turnip, radish, cauliflower, etc leaves to wilt for one or two days and then shred (unevenly cut into small pieces). You can use Sometimes roots of the plants too, but not all the plants, raddish or turnip, etc.  You can mix roots of radish with the leaves and smashed together. Don' make it too small while smashing. 

 

Put those smashed stuffs into a wooden, earthenware or in glassjar very compressed. Close tightly the mouth of the container. Put it in safe and sunny place. It may be placed in an open place. Don't check it often. After few days let's say 3 days check the acidity (sourness), you can know if it is ready from it's strong smell.

 

Dry it then under the sun. After few days take it off the sun and Taste it. If it taste Gundruk, you are done. Mix it in any vegetable and eat it. Don't try to cook it. You can't cook Gundruk.