Wash your ingredients to remove dirt and grit.
Chop scallions into 1-inch pieces. The nasturtium leaves can remain whole. Separate the radish tops from the radish bodies. Slice the bodies and chop the tops into 1-inch pieces.
In a food processor or high-speed blender, purée ginger, garlic, gochujang, gochugaru, fish sauce, salt, and sugar.
Combine all ingredients and put into your fermentation vessel; a Mason jar works just fine.
Fill a Ziploc bag with water and place inside another Ziploc bag, to weigh down the solids. Fasten a towel with a rubber band fastened over the top of the jar to prevent bugs from getting in.
Leave on a countertop at room temperature for two weeks, then enjoy.