Separate the noodles. If you’ve bought fresh steamed rice noodles, rub them with the dark soy sauce. If they’ve been refrigerated they may be stiff, so leave them on the kitchen bench at room temperature to soften a little.
Heat a dry wok and spread the noodles over its surface, allowing them to soften, brown and char until they even appear burnt in parts, before lifting and turning the noodles. If the noodles stick to the wok, add a little oil. If they stick to each other, they are well and truly ready. Once the noodles are done, divide them between two bowls and cover with a clean tea towel to keep them warm.
In a mortar and pestle, crush the garlic and salt, and fry it in oil in the same wok (wiped clean with a paper towel) until fragrant, then add the chicken and fry until sealed.
Add the yellow bean sauce and fry for a minute, then add the pepper and chicken stock, bring to the boil, then add the sugar and Chinese broccoli or bok choy, and turn the heat down.
Simmer the chicken until cooked and the broccoli or bok choy have wilted, then pour in the tapioca slurry, and stir constantly until the sauce thickens to a gravy-like consistency, and is almost translucent and “pleasingly glutinous” as David Thompson says.
Add the light soy and fish sauce, and taste – it should be “salty, sweet and smoky” – and adjust the seasoning to your palate.
To plate, you could pour the chicken gravy over the noodles, or return the noodles to the wok and combine well so that the gravy coats the noodles, then divide between the bowls.
Sprinkle with white pepper and serve with fish sauce, white sugar, roasted chilli powder and sliced chillies steeped in vinegar.