Cut Chinese cabbages into serving sizes. Traditionally, cabbages are not cutting into serving sizes and put sauces between leaves.
However, this way is much easier to handle! So cut cabbages.

Divid them into hard parts and tender leaves.

Wash them under running water and drain them in a colander.

In a big bowl or a big pan, sprinkle salt on to harder leaves and pour water. (The amount of salt is 10-12% of cabbage and water is 5 times of salt). Then put a plate and put something as a weight.

While waiting for the cabbage to dry, make the sauce. (optional "dashi" stock) If you have kelp and niboshi, boil water. Pour over kelp and niboshi and leave until it becomes room temperature. This “dashi” will gives depths to Kimuchi. You only need small amount (30ml, 2 Tablespoon) for this but you and use rest for other dishes.

Peel the ginger. Please use tea spoon to peel it. It is the safest and easiest way to peel ginger. Usually, Brtish people do not know about it. Peel the garlic as well.

Put peeled ginger, garlic and apple in a food processor. Make purée.

Mix two types of chilli powders in a bowl and mix well. Use coarser and finer ones, if you do not have two types, just use one. Try to use a finer chilli and coarser chilli which gives better flavours. But if you cannot find two types of chilli powders, just used one. Mix both chillies well in a bowl. If you have Korean chilli powders, you probably need more than UK ones as they are milder and they are better for Kimchi.

Add all sauce ingredients, including the purée and "dashi" stock into a big bowl except the chilli powders and mix them well. Please start to add less than half of the chilli powder mix. Then, add chilli powder mix little by little to suit your taste. If you add all at once it may become too hot for you and it would be impossible to be undone. Therefore, please start with a smaller quantity. You could add a small portion of your former Kimchi sauce or Kimchi to accelerate the fermentation.

The beauty of homemade Kimchi is you can make as you like. You could add more garlic, ginger, apples, more spring onion, or add chives etc. You could add Kelp, niboshi or dried fish, honey, shiokouji 塩麹 etc to give complex taste when you ferment it. So, play with your sauce and try to find your perfect Kimchi! And you can definitely make much tastier Kimchi than bought ones!

Then, add cabbage and mix them with hands with gloves. I use disposable plastic gloves. Then after mixing well, put them into a clean container. I use a Kilner fermentation bottle set which is great for Kimuchi.