Add chicken stock to a pan and bring to the boil for 3 minutes. Reduce the heat to a simmer. Place both types of miso in the stock (dashi) and slowly loosen up the miso with a spoon as the dashi mixes with it; the paste will slowly melt into the dashi.
Heat a frying pan with a splash of oil and add the leeks, carrots, pak choi, beansprouts and stir-fry for 5 minutes with some salt and white pepper.
Ladle the broth into bowls evenly.
Divide the spring onions and sweetcorn between each bowl, adding the marinated boiled egg, sliced in half, and sprinkling with sesame and chilli oils.
Add the gyozas and enjoy.