Cut the cabbage in half lengthwise, then crossways into 4cm (approx 2") pieces, removing the root end.
Place the cabbage in a large bowl, sprinkle with salt and cover with water.
Leave overnight covered with a clean cloth or plastic wrap.
Drain the cabbage in a colander and rinse well. Squeeze out as much excess liquid as you can and place in a medium bowl.
Add carrot, radish and spring onion (scallion) greens to the bowl.
In a food processor or mortar and pestle, blitz the chilli powder, spring onion whites, garlic, ginger, sugar and miso paste to a rough paste.
PUT ON A PAIR OF RUBBER GLOVES.
Add chilli paste to cabbage and vegetables and ½ cup of water .
Massage to coat and combine.
Spoon cabbage mixture in to a sterilised glass jar, pressing down firmly.
Use a chopstick to press out any bubbles.
Seal with a tight lid and leave in a cool dry place (I use our window sill away from direct light) for 24-36 hours before placing in the fridge for another 3 to 4 days.
Store in the refrigerator once opened and eat within a month. The kimchi will continue to ferment.