I used 1 big Chinese cabbage, about 300g.

1. Cut it into halves, then quarters. Remove the root. And chop it into smaller pieces.
2. Put them all in a big basin. Add in 1 cup water and 6 tbsp salt.
3. Let them marinate in salty water for 2 hours. Remember to flip and toss them a bit every 30 mins. After 2 hours, rinse them under water and drain.
4. For the base: Prepare a sauce pan, add in 2 tbsp flour and 1 cup water. Warm it yo with low heat and keep stirring till it becomes very condensed.
5. Pour the flour paste into the blender, together with 1 chopped onion, 1 tbsp ginger, 8 garlic cloves and 2 tbsp fish sauce. Mix them well and smooth.
6. Pour the base into a big basin. Add in 1/2 cup chili powder. If you like it to be very spicy, you can add more. Mix well.
7. Cut 1 medium carrot into shreds. 5 or 6 stalks spring onion into smaller pieces.
8. Put all the vegetables into the basin and mix with base.

https://flic.kr/p/2isNDV3

Store them in air tight container.