Step 1

Bruise garlic with a pinch of salt with a mortar and pestle, then pound into small pieces, but not to a paste. Transfer to a bowl, add watercress, yellow-bean paste and sugar, toss to combine, and set aside.

Step 2

Heat a seasoned wok (see note) until very hot. Add chilli and char until blackened (4-6 minutes), then add to watercress.

Step 3

Heat oil in wok, add watercress mixture and stir-fry vigorously until wilted (20-30 seconds). Add 1 tbsp water and simmer for a moment, stirring to combine. Season with fish sauce and serve.