The soybean is a wonderfully versatile legume that, when processed, takes many forms. They include soybean milk, soy sauce, miso, doenjang and fermented black beans, and ingredients that many vegetarians and vegans depend on for protein, including bean curd, tempeh and natto.
This vegan dish uses four soy products: salted yellow bean sauce (which comes in a bottle or jar), light soy sauce, bean curd and tempeh. If you're on a gluten-free diet, substitute tamari for the soy sauce.
Many cooks discard the coriander roots, which come attached to the stems and help keep them fresh a little longer. The roots have a lot of flavour, though, and are used often in Thai dishes and in spice pastes. For this recipe, use the root and about 3cm (1 ¼ in) of the lower stems
Put the noodles in a wide bowl and add cool water to cover. Set aside while preparing the other ingredients.
Mince the spring onions and set aside about one-quarter of them for the garnish. Finely mince the fresh coriander roots.
Cut the shallots and garlic cloves in half, then thinly slice them.
Cut the bird’s-eye chillies into thin rounds, shaking out and discarding the seeds as you go. Thinly slice the green and red banana chillies on the diagonal.
Cut the tempeh into small cubes. Cut the bean curd into large, thick matchstick pieces.
Put the yellow bean sauce in a small cup or bowl, add the sugar and stir well. Mix in the soy sauce, rice wine and pepper.
Pour the cooking oil into a clay pot (or a steel or enamelled cast-iron pot) that holds about two litres (2 quarts). Place the pot over a medium flame.
When the oil is hot, add the shallot and garlic and stir for about 45 seconds, or until the shallot is wilted.
Add the bird’s-eye and banana chillies, the coriander root and the larger amount of spring onion. Stir constantly for about 30 seconds, or until fragrant. If necessary, stir in a little more oil.
Drain the noodles in a colander. Put the noodles into the pot and add the sauce mixture, tempeh and bean curd. Pour in 200ml (¾ cup plus 1 tbsp) of vegetable stock, then mix the ingredients thoroughly so the tempeh, bean curd and seasoning are distributed evenly throughout the noodles.
Turn the flame to very low, cover the pot with the lid and cook for about three minutes, mixing often. Taste some of the noodles and if necessary, correct the seasonings. If there’s no liquid at the bottom of the pot, add more vegetable stock.
Cover the pot again and simmer for about two more minutes, or until the noodles are cooked – it should be slightly glossy and moist but not wet.
Scatter the reserved spring onion on top and add some fresh coriander sprigs. Serve immediately.