Chop the rhubarb into 1-2cm chunks and place in a bowl with the salt, mixing to coat the rhubarb. Leave to one side.
Chop the spring onions into greens and whites and place the whites to one side while you shred the greens into strips.
Blend the ginger, garlic and whites of the spring onion to make a paste then add the sugar, miso and gochugaru to combine, adding a little water if needed.
If you don't have a blender then finely chop all of the larger ingredients and mix well.
By now the rhubarb should have 'sweated' and be coated with water. Add the spring onions and chilli paste and mix well.
When the mixture is well combined pack tightly into your jar, one handful at a time pressing down each time to minimise air pockets.
When full clean the rim of the jar and top with a clean cabbage leaf or greaseproof paper, pushing down to submerge.
Replace the lid and label with the date.
Leave out of direct sunlight on a countertop to ferment for a few days. You should see bubbling after 48-72 hours.
Try often and when you enjoy the flavour and texture pop in the fridge. We liked ours after about 2 days, but flavours will continue to develop in the fridge.
