Clean the radishes by scrubbing with a brush and/or scratching off the impurities with a small knife. Peel the skin only if necessary. Then cut each log into thick pieces.
Sprinkl salt and optional 1 tablespoon sugar over the radishes and toss well to coat evenly. Let sit. Drain, saving the liquid in a bowl or pot you'll be using to make the brine.
Dissolve salt in a cup of water and pour over the cabbage. Stir to coat the cabbage pieces with salt water. Let sit. Rotate the bottom ones to the top once.
While the radish is salting, whisk together the glutinous rice powder and water, and simmer over low heat, stirring occasionally, until the mixture thickens into a thin paste.
Place the salted radish and cabbage in a jar or air-tight container. Add the scallion and peppers. Pour the brine over. Stir well together. Taste the brine. Add more salt if necessary.
Leave it out at room temperature for a full day or two until bubbles rise through the brine. Taste again and add more salt if necessary or add more water if too salty.