It doesn’t even really require a recipe, just add whatever you fancy or is in the fridge. Just remember the basics:
stock (any kind, maybe match it with the protein and go for low-salt if using cubes)
sliced chilli or chilli flakes
Heat the stock in a pan and add a few drops of the soy sauce and fish sauce, the chopped chilli, ginger and lemongrass and simmer for a few minutes to flavour the stock. I then added chopped mushrooms, some small prawns and some frozen spinach cubes (a great thing to keep in the freezer). I also quite often make this with chicken, pak choi and beansprouts – it takes a little longer, as it’s nice to poach the chicken in the broth.
No need to add salt as the soy sauce does that for you and make it as spicy as you dare.
I’ll admit that I totally meant to put some rice noodles in at the end but completely forgot, luckily it turns out that it’s nice without noodles too. If adding noodles (they do turn it into a more substantial meal), the straight to wok ones are great but any noodle will cook quickly in the broth anyway.
Ladle into bowls and slurp away!