Tear 300 g green cabbage into large bite-size pieces and place them in a large heatproof bowl.
In a small saucepan, add 4 tbsp water, 1 tbsp toasted sesame oil, 1 tsp Chinese-style chicken bouillon powder, 1 tsp honey, ½ tsp sugar, ½ tsp sea salt, ½ tsp lemon juice, ½ tsp garlic paste, and ¼ tsp ground black pepper. Mix well, heat on low and gently simmer for about 2 minutes.
In a small bowl, mix 1 tbsp water and 1 tsp potato starch (katakuriko) together to make a slurry.
Pour the slurry into the saucepan while whisking, and continue to heat until it thickens to the consistency of maple syrup.
Take it off the heat and immediately pour the hot sauce over the cabbage and toss until every piece is coated, then leave to cool.
If time permits, cover and chill in the fridge for 30 minutes. Sprinkle with toasted white sesame seeds before serving.
Notes
Dry the cabbage first: Water still clinging to washed leaves thins the warm sauce on contact and leaves the bowl watery. Spin or pat the leaves dry before you tear them so the glaze grips.Match the bouillon to your brand: Chinese-style chicken bouillon powders differ in strength. This recipe assumes 1 tsp per 200 ml (my Youki brand), so if yours runs concentrated, use less and taste the warm sauce before it goes on.Use a soft-leaf cabbage: Spring or sweetheart cabbage gives under the hot sauce. A firm winter head or thick napa cabbage stays almost raw with this much heat, so it misses the point of the dish.Pour the sauce hot: The heat lightly wilts the raw leaves, which is the whole trick. A cooled sauce leaves them stiff, so sauce and toss while it is still hot off the stove.Stop at a maple-syrup gloss: Pull the sauce off the heat the moment it coats a spoon. Cooked too long it turns pasty, too little and it stays runny and slides off the leaves.